diff --git a/radio/src/datastructs_private.h b/radio/src/datastructs_private.h
index f9531dc3a..fc4e2c828 100644
--- a/radio/src/datastructs_private.h
+++ b/radio/src/datastructs_private.h
@@ -715,8 +715,9 @@ PACK(struct customSwitch {
 #endif
 
 PACK(struct PartialModel {
+  CUST_ATTR(semver,nullptr,w_semver);
   ModelHeader header;
-  TimerData timers[MAX_TIMERS];
+  ModuleData moduleData[NUM_MODULES];
 });
 
 /*
@@ -756,8 +757,10 @@ PACK(struct USBJoystickChData {
 });
 
 PACK(struct ModelData {
+  // Must match start of PartialModel
   CUST_ATTR(semver,nullptr,w_semver);
   ModelHeader header;
+
   TimerData timers[MAX_TIMERS];
   uint8_t   telemetryProtocol:3;
   uint8_t   thrTrim:1;            // Enable Throttle Trim
diff --git a/radio/src/storage/modelslist.cpp b/radio/src/storage/modelslist.cpp
index 990a62ab9..a3681c544 100644
--- a/radio/src/storage/modelslist.cpp
+++ b/radio/src/storage/modelslist.cpp
@@ -102,11 +102,11 @@ void ModelCell::setModelId(uint8_t moduleIdx, uint8_t id)
   modelId[moduleIdx] = id;
 }
 
-void ModelCell::setRfData(ModelData *model)
+void ModelCell::setRfData(ModelHeader *header, ModuleData* modData)
 {
   for (uint8_t i = 0; i < NUM_MODULES; i++) {
-    modelId[i] = model->header.modelId[i];
-    setRfModuleData(i, &(model->moduleData[i]));
+    modelId[i] = header->modelId[i];
+    setRfModuleData(i, &(modData[i]));
     TRACE("<%s/%i> : %X,%X,%X", strlen(modelName) ? modelName : modelFilename,
           i, moduleData[i].type, moduleData[i].subType, modelId[i]);
   }
@@ -660,17 +660,6 @@ bool ModelMap::renameLabel(const std::string &from, std::string to,
     }
   }
 
-  ModelData *modeldata = (ModelData *)malloc(sizeof(ModelData));
-  if (!modeldata) {
-    TRACE("Labels: Out Of Memory");
-    if (progress != nullptr) progress("", 100); // Kill progress dialog
-    return true;
-  }
-
-  // Force a write of any changes in memory
-  storageCheck(true);
-
-  bool fault = false;
   ModelsVector mods = getModelsByLabel(from);  // Find all models to be renamed
 
   // Scan all these models first, recombine their labels to a csv,
@@ -685,22 +674,26 @@ bool ModelMap::renameLabel(const std::string &from, std::string to,
     if(curlen + csvto.size() - csvfrom.size() > LABELS_LENGTH - 1) {
       TRACE("Labels: Rename Error! Labels too long on %s", model->modelName);
       if (progress != nullptr) progress("", 100); // Kill progress dialog
-      free(modeldata);
       return true;
     }
   }
 
+  // Force a write of any changes in memory
+  storageCheck(true);
+
+  bool fault = false;
   int i = 0;
   for (const auto &modcell : mods) {
     if (progress != nullptr) {
       progress(modcell->modelFilename, (i++) * 100 / mods.size());
     }
 
-    readModelYaml(modcell->modelFilename, (uint8_t *)modeldata,
-                  sizeof(ModelData));
+    PartialModel partial;
+    memclear(&partial, sizeof(PartialModel));
+    readModelYaml(modcell->modelFilename, (uint8_t*)&partial, sizeof(PartialModel));
 
     // Separate Curent CSV
-    LabelsVector lbls = ModelMap::fromCSV(modeldata->header.labels);
+    LabelsVector lbls = ModelMap::fromCSV(partial.header.labels);
 
     // Replace from->to strings
     for (auto &lbl : lbls) {
@@ -714,20 +707,14 @@ bool ModelMap::renameLabel(const std::string &from, std::string to,
     lbls.resize(std::distance(lbls.begin(), last));
 
     // Write back
-    strncpy(modeldata->header.labels, ModelMap::toCSV(lbls).c_str(), LABELS_LENGTH);
-    modeldata->header.labels[LABELS_LENGTH-1] = '\0';
-
-    char path[256];
-    getModelPath(path, modcell->modelFilename);
+    strAppend(partial.header.labels, ModelMap::toCSV(lbls).c_str(), LABELS_LENGTH - 1);
 
     if (modcell == modelslist.getCurrentModel()) {
-      // If working on the current model, write current data to file instead
-      memcpy(g_model.header.labels, modeldata->header.labels, LABELS_LENGTH);
-      fault = (writeFileYaml(path, get_modeldata_nodes(),
-                             (uint8_t *)&g_model, 0) != NULL);
+      // If working on the current model, copy new labels mark dirty
+      memcpy(g_model.header.labels, partial.header.labels, LABELS_LENGTH);
+      storageDirty(EE_MODEL);
     } else {
-      fault = (writeFileYaml(path, get_modeldata_nodes(),
-                             (uint8_t *)modeldata, 0) != NULL);
+      fault = writeModelLabels(modcell, partial.header.labels);
     }
 #if defined(SIMU)
     sleep_ms(100);
@@ -745,8 +732,6 @@ bool ModelMap::renameLabel(const std::string &from, std::string to,
   // Make sure to leave at 100, to kill rename dialog
   if (progress != nullptr) progress("", 100);
 
-  free(modeldata);
-
   // Issue a rescan all of all models.
   modelslist.clear();
   modelslist.load();
@@ -808,6 +793,122 @@ bool ModelMap::removeModels(ModelCell *cell)
   return rv;
 }
 
+/**
+ * @brief Update the labels in an existing model yaml file on SD card
+ * 
+ * @param cell Model to update
+ * @return true Success
+ * @return false Failure
+ */
+bool ModelMap::writeModelLabels(ModelCell* cell, const char* labels)
+{
+  TRACE("Updating labels in %s",cell->modelFilename);
+
+  UINT bytes_cnt;
+  char buf[512];
+  char tempPath[256];
+  FIL out;
+  FIL file;
+
+  // Read exiting model header
+  PartialModel partial;
+  memclear(&partial, sizeof(PartialModel));
+  readModelYaml(cell->modelFilename, (uint8_t*)&partial, sizeof(PartialModel));
+
+  // Update header with new labels
+  strAppend(partial.header.labels, labels, LABELS_LENGTH - 1);
+  // Remove module data - only want to write the header
+  memclear(&partial.moduleData, sizeof(ModuleData) * NUM_MODULES);
+
+  // Write new header to a temp file
+  getModelPath(tempPath, "tmp.yml");
+  if (writeFileYaml(tempPath, get_partialmodel_nodes(), (uint8_t *)&partial, 0) != NULL) {
+    TRACE("ERROR writing temp model file");
+    f_unlink(tempPath);
+    return false;
+  }
+
+  // Open tmp file for appending
+  FRESULT result = f_open(&out, tempPath, FA_OPEN_EXISTING | FA_WRITE | FA_OPEN_APPEND);
+  if (result != FR_OK) {
+    TRACE("ERROR opening temp file");
+    f_unlink(tempPath);
+    return false;
+  }
+
+  // Copy rest of model yaml from original file to temp file
+  getModelPath(buf, cell->modelFilename);
+  result = f_open(&file, buf, FA_OPEN_EXISTING | FA_READ);
+  if (result != FR_OK) {
+    f_close(&out);
+    f_unlink(tempPath);
+    return false;
+  }
+
+  // Read old header - assumes header fits within first 512 bytes
+  // header has not changed significantly for a long time so should be safe
+  result = f_read(&file, buf, sizeof(buf), &bytes_cnt);
+  if (result != FR_OK) {
+    f_close(&out);
+    f_close(&file);
+    f_unlink(tempPath);
+    return false;
+  }
+
+  // Find header section
+  int n = 0;
+  while (n < sizeof(buf) - 7 && strncmp(&buf[n], "header:", 7) != 0)
+    n += 1;
+
+  if (n >= sizeof(buf) - 7) {
+    TRACE("ERROR model header not found in %s", cell->modelFilename);
+    f_close(&out);
+    f_close(&file);
+    f_unlink(tempPath);
+    return false;
+  }
+
+  // Skip header section - look for next section after 'header:'
+  do {
+    // Skip current line
+    while (n < sizeof(buf) && buf[n] != '\n') n += 1;
+    n += 1;
+  } while ((n < sizeof(buf)) && buf[n] == ' ');
+
+  if (n >= sizeof(buf)) {
+    TRACE("ERROR could not match model header in %s", cell->modelFilename);
+    f_close(&out);
+    f_close(&file);
+    f_unlink(tempPath);
+    return false;
+  }
+
+  // Write remainder of first buffer after header
+  result = f_write(&out, &buf[n], sizeof(buf) - n, &bytes_cnt);
+  // Block copy the rest of the original file to the temp file
+  while (result == FR_OK && bytes_cnt != 0) {
+    result = f_read(&file, buf, sizeof(buf), &bytes_cnt);
+    if (result == FR_OK && bytes_cnt != 0)
+      result = f_write(&out, buf, bytes_cnt, &bytes_cnt);
+  }
+
+  f_close(&out);
+  f_close(&file);
+
+  if (result != FR_OK) {
+    TRACE("ERROR copying to temp file");
+    f_unlink(tempPath);
+    return false;
+  }
+
+  // Delete original file and rename temp file
+  getModelPath(buf, cell->modelFilename);
+  f_unlink(buf);
+  f_rename(tempPath, buf);
+
+  return true;
+}
+
 /**
  * @brief Opens a model.yml File and writes labels data into it.
  * @details If the cell is current model then write the labels data to g_model
@@ -829,25 +930,7 @@ bool ModelMap::updateModelFile(ModelCell *cell)
     return false;
   }
 
-  ModelData *modeldata = (ModelData *)malloc(sizeof(ModelData));
-  if (!modeldata) {
-    TRACE("Labels: Out Of Memory");
-    return true;
-  }
-
-  bool fault = false;
-  readModelYaml(cell->modelFilename, (uint8_t *)modeldata, sizeof(ModelData));
-
-  strncpy(modeldata->header.labels, ModelMap::toCSV(getLabelsByModel(cell)).c_str(),
-          LABELS_LENGTH - 1);
-  modeldata->header.labels[LABELS_LENGTH - 1] = '\0';
-
-  char path[256];
-  getModelPath(path, cell->modelFilename);
-  fault = (writeFileYaml(path, get_modeldata_nodes(), (uint8_t *)modeldata, 0) !=
-           NULL);
-
-  free(modeldata);
+  bool fault = writeModelLabels(cell, ModelMap::toCSV(getLabelsByModel(cell)).c_str());
 
 #if defined(DEBUG_TIMERS)
   DEBUG_TIMER_SAMPLE(debugTimerYamlScan);
@@ -930,28 +1013,23 @@ void ModelMap::updateModelCell(ModelCell *cell)
 {
   modelslabels.removeModels(cell);
 
-  ModelData *model = (ModelData *)malloc(sizeof(ModelData));
-  if (!model) {
-    TRACE("Labels: Out Of Memory");
-    return;
-  }
-
   TRACE("Labels: Updating model %s", cell->modelFilename);
-  readModelYaml(cell->modelFilename, (uint8_t *)model, sizeof(ModelData));
-  strncpy(cell->modelName, model->header.name, LEN_MODEL_NAME);
-  cell->modelName[LEN_MODEL_NAME] = '\0';
-  strncpy(cell->modelBitmap, model->header.bitmap, LEN_BITMAP_NAME);
-  cell->modelBitmap[LEN_BITMAP_NAME] = '\0';
-  LabelsVector labels = ModelMap::fromCSV(model->header.labels);
+
+  PartialModel partial;
+  memclear(&partial, sizeof(PartialModel));
+  readModelYaml(cell->modelFilename, (uint8_t*)&partial, sizeof(PartialModel));
+
+  strAppend(cell->modelName, partial.header.name, LEN_MODEL_NAME);
+  strAppend(cell->modelBitmap, partial.header.bitmap, LEN_BITMAP_NAME);
+  LabelsVector labels = ModelMap::fromCSV(partial.header.labels);
   for(const auto &lbl : labels ) {
     modelslabels.addLabelToModel(lbl,cell);
   }
 
   // Save Module Data
-  cell->setRfData(model);
+  cell->setRfData(&partial.header, partial.moduleData);
 
   cell->_isDirty = false;
-  free(model);
 }
 
 /**
@@ -1326,13 +1404,11 @@ void ModelsList::updateCurrentModelCell()
 {
   if (currentModel) {
 #if LEN_BITMAP_NAME > 0
-    strncpy(currentModel->modelBitmap, g_model.header.bitmap, LEN_BITMAP_NAME);
-    currentModel->modelBitmap[LEN_BITMAP_NAME] = '\0';
+    strAppend(currentModel->modelBitmap, g_model.header.bitmap, LEN_BITMAP_NAME);
 #endif
-    strncpy(currentModel->modelFilename, g_eeGeneral.currModelFilename, LEN_MODEL_FILENAME);
-    currentModel->modelFilename[LEN_MODEL_FILENAME] = '\0';
+    strAppend(currentModel->modelFilename, g_eeGeneral.currModelFilename, LEN_MODEL_FILENAME);
     currentModel->setModelName(g_model.header.name);
-    currentModel->setRfData(&g_model);
+    currentModel->setRfData(&g_model.header, g_model.moduleData);
     modelslabels.setDirty();
   } else {
     TRACE("ModelList Error - No Current Model");
diff --git a/radio/src/storage/modelslist.h b/radio/src/storage/modelslist.h
index fe2e2e2e4..d06934442 100644
--- a/radio/src/storage/modelslist.h
+++ b/radio/src/storage/modelslist.h
@@ -43,7 +43,7 @@
 
 #define DEFAULT_MODEL_SORT NAME_ASC
 
-struct ModelData;
+struct ModelHeader;
 struct ModuleData;
 
 struct SimpleModuleData {
@@ -80,7 +80,7 @@ class ModelCell
 
   void setModelName(char *name);
   void setModelName(char *name, uint8_t len);
-  void setRfData(ModelData *model);
+  void setRfData(ModelHeader *header, ModuleData* moduleData);
 
   void setModelId(uint8_t moduleIdx, uint8_t id);
   void setRfModuleData(uint8_t moduleIdx, ModuleData *modData);
@@ -168,6 +168,8 @@ class ModelMap : protected std::multimap<uint16_t, ModelCell *>
   void updateModelCell(ModelCell *);
   bool removeModels(ModelCell *);
 
+  bool writeModelLabels(ModelCell*, const char*);
+
  protected:
   ModelsSortBy _sortOrder = DEFAULT_MODEL_SORT;
   bool _isDirty = true;
diff --git a/radio/src/storage/yaml/yaml_datastructs_128x64.cpp b/radio/src/storage/yaml/yaml_datastructs_128x64.cpp
index e597a33af..b3bb957b7 100644
--- a/radio/src/storage/yaml/yaml_datastructs_128x64.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_128x64.cpp
@@ -881,8 +881,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 96, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 96, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_c14.cpp b/radio/src/storage/yaml/yaml_datastructs_c14.cpp
index 443f73f2d..c0edf57f6 100644
--- a/radio/src/storage/yaml/yaml_datastructs_c14.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_c14.cpp
@@ -977,8 +977,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_f16.cpp b/radio/src/storage/yaml/yaml_datastructs_f16.cpp
index 6172ec13f..6ae2ad493 100644
--- a/radio/src/storage/yaml/yaml_datastructs_f16.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_f16.cpp
@@ -978,8 +978,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_gx12.cpp b/radio/src/storage/yaml/yaml_datastructs_gx12.cpp
index 3abdb34d3..073cee189 100644
--- a/radio/src/storage/yaml/yaml_datastructs_gx12.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_gx12.cpp
@@ -929,8 +929,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 96, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 96, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_gx15.cpp b/radio/src/storage/yaml/yaml_datastructs_gx15.cpp
index 5933e4aaf..274ab0333 100644
--- a/radio/src/storage/yaml/yaml_datastructs_gx15.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_gx15.cpp
@@ -1026,8 +1026,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_nb4p.cpp b/radio/src/storage/yaml/yaml_datastructs_nb4p.cpp
index 652730433..13244fbd5 100644
--- a/radio/src/storage/yaml/yaml_datastructs_nb4p.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_nb4p.cpp
@@ -968,8 +968,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_nv14.cpp b/radio/src/storage/yaml/yaml_datastructs_nv14.cpp
index ad8eb54bb..3183ba727 100644
--- a/radio/src/storage/yaml/yaml_datastructs_nv14.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_nv14.cpp
@@ -976,8 +976,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_pa01.cpp b/radio/src/storage/yaml/yaml_datastructs_pa01.cpp
index 9a01dc9fc..517ab5ddf 100644
--- a/radio/src/storage/yaml/yaml_datastructs_pa01.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_pa01.cpp
@@ -1025,8 +1025,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_pl18.cpp b/radio/src/storage/yaml/yaml_datastructs_pl18.cpp
index 31bde01d5..66bedbcec 100644
--- a/radio/src/storage/yaml/yaml_datastructs_pl18.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_pl18.cpp
@@ -976,8 +976,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_pl18u.cpp b/radio/src/storage/yaml/yaml_datastructs_pl18u.cpp
index 3548ae842..17e0ed75c 100644
--- a/radio/src/storage/yaml/yaml_datastructs_pl18u.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_pl18u.cpp
@@ -968,8 +968,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_st16.cpp b/radio/src/storage/yaml/yaml_datastructs_st16.cpp
index 667ad4317..6d8a62570 100644
--- a/radio/src/storage/yaml/yaml_datastructs_st16.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_st16.cpp
@@ -1025,8 +1025,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_t15.cpp b/radio/src/storage/yaml/yaml_datastructs_t15.cpp
index cc6d78672..bc3331313 100644
--- a/radio/src/storage/yaml/yaml_datastructs_t15.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_t15.cpp
@@ -1003,8 +1003,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_t15pro.cpp b/radio/src/storage/yaml/yaml_datastructs_t15pro.cpp
index d37bf8576..e739e85fe 100644
--- a/radio/src/storage/yaml/yaml_datastructs_t15pro.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_t15pro.cpp
@@ -1025,8 +1025,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_t20.cpp b/radio/src/storage/yaml/yaml_datastructs_t20.cpp
index 8fe2d3e42..7eb523e79 100644
--- a/radio/src/storage/yaml/yaml_datastructs_t20.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_t20.cpp
@@ -907,8 +907,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 96, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 96, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_t22.cpp b/radio/src/storage/yaml/yaml_datastructs_t22.cpp
index d37bf8576..e739e85fe 100644
--- a/radio/src/storage/yaml/yaml_datastructs_t22.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_t22.cpp
@@ -1025,8 +1025,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_tpro.cpp b/radio/src/storage/yaml/yaml_datastructs_tpro.cpp
index ed10a9a02..5628d781b 100644
--- a/radio/src/storage/yaml/yaml_datastructs_tpro.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_tpro.cpp
@@ -907,8 +907,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 96, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 96, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_tx15.cpp b/radio/src/storage/yaml/yaml_datastructs_tx15.cpp
index 5933e4aaf..274ab0333 100644
--- a/radio/src/storage/yaml/yaml_datastructs_tx15.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_tx15.cpp
@@ -1026,8 +1026,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_tx16smk3.cpp b/radio/src/storage/yaml/yaml_datastructs_tx16smk3.cpp
index 6a8f45507..0e16f08ce 100644
--- a/radio/src/storage/yaml/yaml_datastructs_tx16smk3.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_tx16smk3.cpp
@@ -1027,8 +1027,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_v12.cpp b/radio/src/storage/yaml/yaml_datastructs_v12.cpp
index 026401122..56f73b7bd 100644
--- a/radio/src/storage/yaml/yaml_datastructs_v12.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_v12.cpp
@@ -1021,8 +1021,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_x10.cpp b/radio/src/storage/yaml/yaml_datastructs_x10.cpp
index 764884183..31b8131cc 100644
--- a/radio/src/storage/yaml/yaml_datastructs_x10.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_x10.cpp
@@ -978,8 +978,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 1048, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_x9d.cpp b/radio/src/storage/yaml/yaml_datastructs_x9d.cpp
index ff690575c..3f5d78614 100644
--- a/radio/src/storage/yaml/yaml_datastructs_x9d.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_x9d.cpp
@@ -883,8 +883,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 192, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_x9dp2019.cpp b/radio/src/storage/yaml/yaml_datastructs_x9dp2019.cpp
index ff690575c..3f5d78614 100644
--- a/radio/src/storage/yaml/yaml_datastructs_x9dp2019.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_x9dp2019.cpp
@@ -883,8 +883,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 192, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_x9e.cpp b/radio/src/storage/yaml/yaml_datastructs_x9e.cpp
index 7cee0fadf..774550d85 100644
--- a/radio/src/storage/yaml/yaml_datastructs_x9e.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_x9e.cpp
@@ -884,8 +884,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 192, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 136, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_xlite.cpp b/radio/src/storage/yaml/yaml_datastructs_xlite.cpp
index a00e82368..c86d9498d 100644
--- a/radio/src/storage/yaml/yaml_datastructs_xlite.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_xlite.cpp
@@ -882,8 +882,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 96, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 96, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/storage/yaml/yaml_datastructs_xlites.cpp b/radio/src/storage/yaml/yaml_datastructs_xlites.cpp
index 0ec87c706..1351124a6 100644
--- a/radio/src/storage/yaml/yaml_datastructs_xlites.cpp
+++ b/radio/src/storage/yaml/yaml_datastructs_xlites.cpp
@@ -887,8 +887,9 @@ static const struct YamlNode struct_ModelData[] = {
   YAML_END
 };
 static const struct YamlNode struct_PartialModel[] = {
+  YAML_CUSTOM("semver",nullptr,w_semver),
   YAML_STRUCT("header", 96, struct_ModelHeader, NULL),
-  YAML_ARRAY("timers", 96, 3, struct_TimerData, NULL),
+  YAML_ARRAY("moduleData", 232, 2, struct_ModuleData, NULL),
   YAML_END
 };
 
diff --git a/radio/src/tests/modelslist.cpp b/radio/src/tests/modelslist.cpp
new file mode 100644
index 000000000..1d2bb3988
--- /dev/null
+++ b/radio/src/tests/modelslist.cpp
@@ -0,0 +1,166 @@
+/*
+ * Copyright (C) EdgeTX
+ *
+ * Based on code named
+ *   opentx - https://github.com/opentx/opentx
+ *   th9x - http://code.google.com/p/th9x
+ *   er9x - http://code.google.com/p/er9x
+ *   gruvin9x - http://code.google.com/p/gruvin9x
+ *
+ * License GPLv2: http://www.gnu.org/licenses/gpl-2.0.html
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+// Targeted tests for the PartialModel/ModelHeader restructuring in PR #7709
+// ("fix(color): modifying model labels may corrupt model yaml files").
+//
+// These deliberately avoid FatFS/SD-card I/O and instead exercise the two
+// things that PR touches which can silently drift out of sync across the
+// 27 hand-edited yaml_datastructs_*.cpp files: the PartialModel YAML node
+// table, and the strAppend() length constants used to write header.labels.
+
+#include "gtests.h"
+
+#include "storage/yaml/yaml_tree_walker.h"
+#include "storage/yaml/yaml_parser.h"
+#include "storage/yaml/yaml_datastructs.h"
+
+// Find an immediate child of an array/struct YamlNode by tag.
+static const YamlNode* findChild(const YamlNode* root, const char* tag)
+{
+  const YamlNode* child = root->u._array.child;
+  for (; child->type != YDT_NONE; child++) {
+    if (child->tag && strcmp(child->tag, tag) == 0) return child;
+  }
+  return nullptr;
+}
+
+// The PR hand-edited struct_PartialModel's "moduleData" YAML_ARRAY entry in
+// 27 generated files to read `YAML_ARRAY("moduleData", <bits>, <NUM_MODULES>,
+// struct_ModuleData, NULL)`, replacing the old "timers" entry. <bits> must
+// equal sizeof(ModuleData)*8 and the element count must equal NUM_MODULES,
+// or the YAML (de)serializer will misalign every field after moduleData in
+// any file that uses struct_PartialModel (readModelYaml/writeModelLabels).
+TEST(PartialModel, ModuleDataNodeMatchesStructLayout)
+{
+  const YamlNode* root = get_partialmodel_nodes();
+  const YamlNode* moduleData = findChild(root, "moduleData");
+  ASSERT_NE(moduleData, nullptr);
+
+  EXPECT_EQ(moduleData->elmts, NUM_MODULES);
+  EXPECT_EQ(moduleData->size, sizeof(ModuleData) * 8);
+}
+
+// Same idea for the "header" entry: its declared bit size must equal
+// sizeof(ModelHeader)*8, or moduleData (and thus every array element after
+// it) parses starting at the wrong bit offset.
+TEST(PartialModel, HeaderNodeMatchesStructLayout)
+{
+  const YamlNode* root = get_partialmodel_nodes();
+  const YamlNode* header = findChild(root, "header");
+  ASSERT_NE(header, nullptr);
+
+  EXPECT_EQ(header->size, sizeof(ModelHeader) * 8);
+}
+
+// PartialModel must be layout-compatible with the start of ModelData, per
+// the comment added at datastructs_private.h ModelData::header ("Must match
+// start of PartialModel") -- readModelCell()/updateModelCell() rely on this
+// so that data read into a PartialModel (a stack buffer) reflects the same
+// bytes that would land in the corresponding fields of a full ModelData.
+TEST(PartialModel, HeaderOffsetMatchesModelData)
+{
+  EXPECT_EQ(offsetof(PartialModel, header), offsetof(ModelData, header));
+}
+
+// End-to-end: parse the same YAML "header:" block once into a PartialModel
+// and once into a full ModelData, and check they agree field-for-field.
+// This is the strongest guard against the two generated tables silently
+// drifting apart, because it doesn't hardcode any bit offsets itself -- it
+// just requires both parsers to produce the same result for the same input.
+TEST(PartialModel, HeaderParsesIdenticallyToModelData)
+{
+  static const char yaml[] =
+      "header: \n"
+      "   name: \"Tst Name\"\n"
+      "   modelId: [3, 5]\n"
+#if LEN_BITMAP_NAME > 0
+      "   bitmap: \"pic.bmp\"\n"
+#endif
+#if defined(STORAGE_MODELSLIST)
+      "   labels: \"alpha,bravo\"\n"
+#endif
+      ;
+
+  PartialModel partial;
+  memclear(&partial, sizeof(partial));
+  {
+    YamlTreeWalker tree;
+    tree.reset(get_partialmodel_nodes(), (uint8_t*)&partial);
+    YamlParser yp;
+    yp.init(YamlTreeWalker::get_parser_calls(), &tree);
+    yp.parse(yaml, sizeof(yaml) - 1);
+  }
+
+  ModelData model;
+  memclear(&model, sizeof(model));
+  {
+    YamlTreeWalker tree;
+    tree.reset(get_modeldata_nodes(), (uint8_t*)&model);
+    YamlParser yp;
+    yp.init(YamlTreeWalker::get_parser_calls(), &tree);
+    yp.parse(yaml, sizeof(yaml) - 1);
+  }
+
+  EXPECT_STREQ(partial.header.name, model.header.name);
+  EXPECT_EQ(0, memcmp(partial.header.modelId, model.header.modelId,
+                       sizeof(model.header.modelId)));
+#if LEN_BITMAP_NAME > 0
+  EXPECT_STREQ(partial.header.bitmap, model.header.bitmap);
+#endif
+#if defined(STORAGE_MODELSLIST)
+  EXPECT_STREQ(partial.header.labels, model.header.labels);
+#endif
+
+  // Sanity: the fixture actually populated something non-zero, otherwise a
+  // parser that silently no-ops on both sides would pass trivially.
+  EXPECT_STREQ("Tst Name", partial.header.name);
+}
+
+// Behavioural contract for ModelHeader::labels: it holds the CSV-joined
+// list of *every* label attached to a model (declared as
+// char[LABELS_LENGTH], currently 100 bytes) -- as distinct from the length
+// of one individual label name (LABEL_LENGTH, 16 bytes). A model with
+// several labels attached should keep all of them when this field gets
+// (re)written, up to the field's own declared capacity, not just as much
+// as would fit in a single label name.
+//
+// header.labels only exists on targets with STORAGE_MODELSLIST.
+#if defined(STORAGE_MODELSLIST)
+TEST(PartialModel, LabelsFieldRetainsFullCsvUpToItsOwnCapacity)
+{
+  PartialModel partial;
+  memclear(&partial, sizeof(partial));
+
+  // A multi-label CSV comfortably inside LABELS_LENGTH, but longer than a
+  // single LABEL_LENGTH-sized name -- i.e. more than one label attached.
+  const char* csv = "alpha,bravo,charlie,delta,echo";
+  ASSERT_GT(strlen(csv), (size_t)LABEL_LENGTH);
+  ASSERT_LT(strlen(csv), (size_t)LABELS_LENGTH);
+
+  strAppend(partial.header.labels, csv, LABELS_LENGTH - 1);
+
+  EXPECT_STREQ(csv, partial.header.labels)
+      << "header.labels should retain the full label list up to "
+         "LABELS_LENGTH-1 characters, not just a single label name's "
+         "worth.";
+}
+#endif // defined(STORAGE_MODELSLIST)