diff --git a/src/core/featuremodel.cpp b/src/core/featuremodel.cpp
index 7ed7efa072..e532f577f4 100644
--- a/src/core/featuremodel.cpp
+++ b/src/core/featuremodel.cpp
@@ -126,6 +126,36 @@ void FeatureModel::setFeatures( const QList<QgsFeature> &features )
   endResetModel();
 }
 
+QVariantList FeatureModel::featuresVariant() const
+{
+  QVariantList featuresVariant;
+
+  featuresVariant.reserve( mFeatures.size() );
+  for ( const QgsFeature &feature : mFeatures )
+  {
+    // Pack the custom QgsFeature object into a QVariant safely
+    featuresVariant.append( QVariant::fromValue( feature ) );
+  }
+
+  return featuresVariant;
+}
+
+void FeatureModel::setFeaturesVariant( const QVariantList &features )
+{
+  QList<QgsFeature> featuresList;
+  featuresList.reserve( features.size() );
+
+  for ( const QVariant &variant : features )
+  {
+    if ( variant.canConvert<QgsFeature>() )
+    {
+      featuresList.append( variant.value<QgsFeature>() );
+    }
+  }
+
+  setFeatures( featuresList );
+}
+
 void FeatureModel::setCurrentLayer( QgsVectorLayer *layer )
 {
   if ( layer == mLayer )
diff --git a/src/core/featuremodel.h b/src/core/featuremodel.h
index b52abdf8a3..d7334db7d6 100644
--- a/src/core/featuremodel.h
+++ b/src/core/featuremodel.h
@@ -35,7 +35,7 @@ class FeatureModel : public QAbstractListModel
     Q_OBJECT
     Q_PROPERTY( FeatureModel::ModelModes modelMode READ modelMode WRITE setModelMode NOTIFY modelModeChanged )
     Q_PROPERTY( QgsFeature feature READ feature WRITE setFeature NOTIFY featureChanged )
-    Q_PROPERTY( QList<QgsFeature> features READ features WRITE setFeatures NOTIFY featuresChanged )
+    Q_PROPERTY( QVariantList features READ featuresVariant WRITE setFeaturesVariant NOTIFY featuresChanged )
     Q_PROPERTY( QgsFeature linkedParentFeature READ linkedParentFeature WRITE setLinkedParentFeature NOTIFY linkedParentFeatureChanged )
     Q_PROPERTY( QgsRelation linkedRelation READ linkedRelation WRITE setLinkedRelation NOTIFY linkedRelationChanged )
     Q_PROPERTY( QString linkedRelationOrderingField READ linkedRelationOrderingField WRITE setLinkedRelationOrderingField NOTIFY linkedRelationOrderingFieldChanged )
@@ -91,6 +91,10 @@ class FeatureModel : public QAbstractListModel
 
     void setFeatures( const QList<QgsFeature> &features );
 
+    QVariantList featuresVariant() const;
+
+    void setFeaturesVariant( const QVariantList &features );
+
     /**
      * Return the features list for passing it around in QML
      */
diff --git a/src/core/gridmodel.cpp b/src/core/gridmodel.cpp
index 003e1da49d..48536be6ff 100644
--- a/src/core/gridmodel.cpp
+++ b/src/core/gridmodel.cpp
@@ -449,11 +449,11 @@ void GridModel::update()
       {
         if ( currentLine.intersects( topBorder, &intersectionPoint ) )
         {
-          mAnnotations << GridAnnotation( GridAnnotation::Top, intersectionPoint, xPos );
+          mAnnotations << QVariant::fromValue( GridAnnotation( GridAnnotation::Top, intersectionPoint, xPos ) );
         }
         if ( currentLine.intersects( bottomBorder, &intersectionPoint ) )
         {
-          mAnnotations << GridAnnotation( GridAnnotation::Bottom, intersectionPoint, xPos );
+          mAnnotations << QVariant::fromValue( GridAnnotation( GridAnnotation::Bottom, intersectionPoint, xPos ) );
         }
       }
 
@@ -478,11 +478,11 @@ void GridModel::update()
       {
         if ( currentLine.intersects( leftBorder, &intersectionPoint ) )
         {
-          mAnnotations << GridAnnotation( GridAnnotation::Left, intersectionPoint, yPos );
+          mAnnotations << QVariant::fromValue( GridAnnotation( GridAnnotation::Left, intersectionPoint, yPos ) );
         }
         if ( currentLine.intersects( rightBorder, &intersectionPoint ) )
         {
-          mAnnotations << GridAnnotation( GridAnnotation::Right, intersectionPoint, yPos );
+          mAnnotations << QVariant::fromValue( GridAnnotation( GridAnnotation::Right, intersectionPoint, yPos ) );
         }
       }
 
diff --git a/src/core/gridmodel.h b/src/core/gridmodel.h
index 6e29b137ed..2690bb3a01 100644
--- a/src/core/gridmodel.h
+++ b/src/core/gridmodel.h
@@ -77,7 +77,7 @@ class QFIELD_CORE_EXPORT GridModel : public QObject
     Q_PROPERTY( QString majorLinesPath READ majorLinesPath NOTIFY majorLinesChanged )
     Q_PROPERTY( QString minorLinesPath READ minorLinesPath NOTIFY minorLinesChanged )
     Q_PROPERTY( QString markersPath READ markersPath NOTIFY markersChanged )
-    Q_PROPERTY( QList<GridAnnotation> annotations READ annotations NOTIFY annotationsChanged )
+    Q_PROPERTY( QVariantList annotations READ annotations NOTIFY annotationsChanged )
 
     Q_PROPERTY( bool autoColor READ autoColor WRITE setAutoColor NOTIFY autoColorChanged )
     Q_PROPERTY( QColor majorLineColor READ majorLineColor WRITE setMajorLineColor NOTIFY majorLineColorChanged )
@@ -169,7 +169,7 @@ class QFIELD_CORE_EXPORT GridModel : public QObject
     void setPrepareAnnotations( bool prepare );
 
     //! Returns the grid annotations
-    QList<GridAnnotation> annotations() const { return mAnnotations; }
+    QVariantList annotations() const { return mAnnotations; }
 
     /**
      * Returns whether grid line and marker colors will be automatically assigned to
@@ -320,7 +320,7 @@ class QFIELD_CORE_EXPORT GridModel : public QObject
     QString mMarkersPath;
 
     bool mPrepareAnnotations = false;
-    QList<GridAnnotation> mAnnotations;
+    QVariantList mAnnotations;
 
     bool mAutoColor = false;
     QColor mMajorLineColor = QColor( 0, 0, 0, 100 );
diff --git a/src/core/multifeaturelistmodel.cpp b/src/core/multifeaturelistmodel.cpp
index d36eca227c..e9c3ea0e1b 100644
--- a/src/core/multifeaturelistmodel.cpp
+++ b/src/core/multifeaturelistmodel.cpp
@@ -219,6 +219,21 @@ QList<QgsFeature> MultiFeatureListModel::selectedFeatures()
   return mSourceModel->selectedFeatures();
 }
 
+QVariantList MultiFeatureListModel::selectedFeaturesVariant()
+{
+  QVariantList featuresVariant;
+  const QList<QgsFeature> features = mSourceModel->selectedFeatures();
+
+  featuresVariant.reserve( features.size() );
+  for ( const QgsFeature &feature : features )
+  {
+    // Pack the custom QgsFeature object into a QVariant safely
+    featuresVariant.append( QVariant::fromValue( feature ) );
+  }
+
+  return featuresVariant;
+}
+
 QgsVectorLayer *MultiFeatureListModel::selectedLayer()
 {
   return mFilterLayer.data();
diff --git a/src/core/multifeaturelistmodel.h b/src/core/multifeaturelistmodel.h
index 66b975f7eb..b1b7e929b2 100644
--- a/src/core/multifeaturelistmodel.h
+++ b/src/core/multifeaturelistmodel.h
@@ -33,7 +33,7 @@ class MultiFeatureListModel : public QSortFilterProxyModel
     Q_OBJECT
 
     Q_PROPERTY( int count READ count NOTIFY countChanged )
-    Q_PROPERTY( QList<QgsFeature> selectedFeatures READ selectedFeatures NOTIFY selectedCountChanged )
+    Q_PROPERTY( QVariantList selectedFeatures READ selectedFeaturesVariant NOTIFY selectedCountChanged )
     Q_PROPERTY( QgsVectorLayer *selectedLayer READ selectedLayer NOTIFY selectedLayerChanged )
     Q_PROPERTY( int selectedCount READ selectedCount NOTIFY selectedCountChanged )
     Q_PROPERTY( bool canEditAttributesSelection READ canEditAttributesSelection NOTIFY selectedCountChanged )
@@ -175,6 +175,11 @@ class MultiFeatureListModel : public QSortFilterProxyModel
      */
     QList<QgsFeature> selectedFeatures();
 
+    /**
+     * Returns the list of currently selected features as a QVariantList object.
+     */
+    QVariantList selectedFeaturesVariant();
+
     /**
      * Returns the vector layer within which one or more features are currently selected
      */
diff --git a/src/core/processing/processingalgorithm.cpp b/src/core/processing/processingalgorithm.cpp
index bf1ff24356..06309b98fc 100644
--- a/src/core/processing/processingalgorithm.cpp
+++ b/src/core/processing/processingalgorithm.cpp
@@ -91,6 +91,36 @@ void ProcessingAlgorithm::setInPlaceFeatures( const QList<QgsFeature> &features
   }
 }
 
+QVariantList ProcessingAlgorithm::inPlaceFeaturesVariant() const
+{
+  QVariantList featuresVariant;
+
+  featuresVariant.reserve( mInPlaceFeatures.size() );
+  for ( const QgsFeature &feature : mInPlaceFeatures )
+  {
+    // Pack the custom QgsFeature object into a QVariant safely
+    featuresVariant.append( QVariant::fromValue( feature ) );
+  }
+
+  return featuresVariant;
+}
+
+void ProcessingAlgorithm::setInPlaceFeaturesVariant( const QVariantList &features )
+{
+  QList<QgsFeature> featuresList;
+  featuresList.reserve( features.size() );
+
+  for ( const QVariant &variant : features )
+  {
+    if ( variant.canConvert<QgsFeature>() )
+    {
+      featuresList.append( variant.value<QgsFeature>() );
+    }
+  }
+
+  setInPlaceFeatures( featuresList );
+}
+
 void ProcessingAlgorithm::setParameters( const QVariantMap &parameters )
 {
   if ( mAlgorithmParameters == parameters )
@@ -205,7 +235,7 @@ bool ProcessingAlgorithm::run( bool previewMode )
         {
           for ( const QgsFeature &outputFeature : outputFeatures )
           {
-            mPreviewGeometries << outputFeature.geometry();
+            mPreviewGeometries << QVariant::fromValue( outputFeature.geometry() );
           }
 
           emit previewGeometriesChanged();
@@ -296,7 +326,7 @@ bool ProcessingAlgorithm::run( bool previewMode )
           {
             for ( const QgsFeature &previewFeature : outputFeatures )
             {
-              mPreviewGeometries << previewFeature.geometry();
+              mPreviewGeometries << QVariant::fromValue( previewFeature.geometry() );
             }
 
             emit previewGeometriesChanged();
diff --git a/src/core/processing/processingalgorithm.h b/src/core/processing/processingalgorithm.h
index 138348d1a3..fbdcfaf847 100644
--- a/src/core/processing/processingalgorithm.h
+++ b/src/core/processing/processingalgorithm.h
@@ -45,10 +45,10 @@ class ProcessingAlgorithm : public QObject
 
     Q_PROPERTY( QVariantMap parameters READ parameters WRITE setParameters NOTIFY parametersChanged )
     Q_PROPERTY( QgsVectorLayer *inPlaceLayer READ inPlaceLayer WRITE setInPlaceLayer NOTIFY inPlaceLayerChanged )
-    Q_PROPERTY( QList<QgsFeature> inPlaceFeatures READ inPlaceFeatures WRITE setInPlaceFeatures NOTIFY inPlaceFeaturesChanged )
+    Q_PROPERTY( QVariantList inPlaceFeatures READ inPlaceFeaturesVariant WRITE setInPlaceFeaturesVariant NOTIFY inPlaceFeaturesChanged )
 
     Q_PROPERTY( bool preview READ preview WRITE setPreview NOTIFY previewChanged )
-    Q_PROPERTY( QList<QgsGeometry> previewGeometries READ previewGeometries NOTIFY previewGeometriesChanged )
+    Q_PROPERTY( QVariantList previewGeometries READ previewGeometries NOTIFY previewGeometriesChanged )
 
   public:
     explicit ProcessingAlgorithm( QObject *parent = nullptr );
@@ -98,6 +98,16 @@ class ProcessingAlgorithm : public QObject
      */
     void setInPlaceFeatures( const QList<QgsFeature> &features );
 
+    /**
+     * Returns the vector \a layer for in-place algorithm filter as a QVariantList.
+     */
+    QVariantList inPlaceFeaturesVariant() const;
+
+    /**
+     * Sets the vector \a layer for in-place algorithm filter from a QVariantList.
+     */
+    void setInPlaceFeaturesVariant( const QVariantList &features );
+
     /**
      * Returns the algorithm parameters as a map of parameter names as keys and values.
      */
@@ -123,7 +133,7 @@ class ProcessingAlgorithm : public QObject
     /**
      * Returns a list of geometries previewing the algorithm result using current parameters.
      */
-    QList<QgsGeometry> previewGeometries() const { return mPreviewGeometries; }
+    QVariantList previewGeometries() const { return mPreviewGeometries; }
 
     /**
      * Executes the algorithm.
@@ -170,7 +180,7 @@ class ProcessingAlgorithm : public QObject
     QList<QgsFeature> mInPlaceFeatures;
 
     bool mPreview = false;
-    QList<QgsGeometry> mPreviewGeometries;
+    QVariantList mPreviewGeometries;
 };
 
 #endif // PROCESSINGALGORITHM
diff --git a/src/core/qfieldcloud/qfieldcloudconnection.cpp b/src/core/qfieldcloud/qfieldcloudconnection.cpp
index 525169412e..2a7aec99cd 100644
--- a/src/core/qfieldcloud/qfieldcloudconnection.cpp
+++ b/src/core/qfieldcloud/qfieldcloudconnection.cpp
@@ -305,9 +305,18 @@ bool QFieldCloudConnection::isFetchingAvailableProviders() const
   return mIsFetchingAvailableProviders;
 }
 
-QList<AuthenticationProvider> QFieldCloudConnection::availableProviders() const
+QVariantList QFieldCloudConnection::availableProviders() const
 {
-  return mAvailableProviders.values();
+  const QList<AuthenticationProvider> providers = mAvailableProviders.values();
+  QVariantList providersVariant;
+  providersVariant.reserve( providers.size() );
+
+  for ( const AuthenticationProvider &provider : providers )
+  {
+    providersVariant.append( QVariant::fromValue( provider ) );
+  }
+
+  return providersVariant;
 }
 
 void QFieldCloudConnection::getServerInformation()
diff --git a/src/core/qfieldcloud/qfieldcloudconnection.h b/src/core/qfieldcloud/qfieldcloudconnection.h
index 2df1668bb1..ca4c0fca27 100644
--- a/src/core/qfieldcloud/qfieldcloudconnection.h
+++ b/src/core/qfieldcloud/qfieldcloudconnection.h
@@ -83,7 +83,7 @@ class QFieldCloudConnection : public QObject
 
     Q_PROPERTY( CloudUserInformation userInformation READ userInformation NOTIFY userInformationChanged )
 
-    Q_PROPERTY( QList<AuthenticationProvider> availableProviders READ availableProviders NOTIFY availableProvidersChanged )
+    Q_PROPERTY( QVariantList availableProviders READ availableProviders NOTIFY availableProvidersChanged )
     Q_PROPERTY( bool isFetchingAvailableProviders READ isFetchingAvailableProviders NOTIFY isFetchingAvailableProvidersChanged )
 
     Q_PROPERTY( CloudServerInformation serverInformation READ serverInformation NOTIFY serverInformationChanged )
@@ -175,7 +175,7 @@ class QFieldCloudConnection : public QObject
     Q_INVOKABLE void getSubscriptionInformation( const QString &user );
 
     Q_INVOKABLE void getServerInformation();
-    QList<AuthenticationProvider> availableProviders() const;
+    QVariantList availableProviders() const;
     bool isFetchingAvailableProviders() const;
 
     CloudServerInformation serverInformation() const { return mServerInformation; }
diff --git a/src/core/trackingmodel.cpp b/src/core/trackingmodel.cpp
index 2588c0ad93..452debddc8 100644
--- a/src/core/trackingmodel.cpp
+++ b/src/core/trackingmodel.cpp
@@ -102,6 +102,22 @@ bool TrackingModel::featureInTracking( QgsVectorLayer *layer, const QgsFeatureId
   return false;
 }
 
+bool TrackingModel::featuresInTracking( QgsVectorLayer *layer, const QVariantList &features )
+{
+  QList<QgsFeature> featuresList;
+
+  featuresList.reserve( features.size() );
+  for ( const QVariant &variant : features )
+  {
+    if ( variant.canConvert<QgsFeature>() )
+    {
+      featuresList.append( variant.value<QgsFeature>() );
+    }
+  }
+
+  return featuresInTracking( layer, featuresList );
+}
+
 bool TrackingModel::featuresInTracking( QgsVectorLayer *layer, const QList<QgsFeature> &features )
 {
   auto it = trackerIterator( layer );
diff --git a/src/core/trackingmodel.h b/src/core/trackingmodel.h
index cd08d655e7..7956a5bb81 100644
--- a/src/core/trackingmodel.h
+++ b/src/core/trackingmodel.h
@@ -64,7 +64,9 @@ class TrackingModel : public QAbstractItemModel
     //! Returns TRUE if the \a featureId is attached to a vector \a layer tracking session.
     Q_INVOKABLE bool featureInTracking( QgsVectorLayer *layer, QgsFeatureId featureId );
     //! Returns TRUE if the list of \a features is attached to a vector \a layer tracking session.
-    Q_INVOKABLE bool featuresInTracking( QgsVectorLayer *layer, const QList<QgsFeature> &features );
+    Q_INVOKABLE bool featuresInTracking( QgsVectorLayer *layer, const QVariantList &features );
+    //! Returns TRUE if the list of \a features is attached to a vector \a layer tracking session.
+    bool featuresInTracking( QgsVectorLayer *layer, const QList<QgsFeature> &features );
     //! Returns TRUE if the vector \a layer has a tracking session.
     Q_INVOKABLE bool layerInTracking( QgsVectorLayer *layer ) const;
     //! Returns TRUE if the vector \a layer has an active tracking session.
diff --git a/src/qml/FeatureListForm.qml b/src/qml/FeatureListForm.qml
index 51f733e592..648b79bcea 100644
--- a/src/qml/FeatureListForm.qml
+++ b/src/qml/FeatureListForm.qml
@@ -666,8 +666,8 @@ Pane {
     }
 
     onDeleteClicked: {
-      var selectedFeatures = featureFormList.selection.model.selectedFeatures;
-      var selectedFeature = selectedFeatures && selectedFeatures.length > 0 ? selectedFeatures[0] : null;
+      let selectedFeatures = featureFormList.selection.model.selectedFeatures;
+      let selectedFeature = selectedFeatures && selectedFeatures.length > 0 ? selectedFeatures[0] : null;
       if (selectedFeature && featureFormList.selection.focusedLayer && trackingModel.featureInTracking(featureFormList.selection.focusedLayer, selectedFeature)) {
         displayToast(qsTr("A number of features are being tracked, stop tracking to delete those"));
       } else {
diff --git a/src/qml/editorwidgets/ExternalResource.qml b/src/qml/editorwidgets/ExternalResource.qml
index 4d377de739..f472209d3c 100644
--- a/src/qml/editorwidgets/ExternalResource.qml
+++ b/src/qml/editorwidgets/ExternalResource.qml
@@ -187,7 +187,7 @@ EditorWidgetBase {
     id: audioAnalyzer
     barCount: 80
     onReady: bars => {
-      audioWaveformRepeater.model = bars;
+      audioWaveformRepeater.model = Array.from(bars);
     }
   }
 
diff --git a/src/qml/editorwidgets/relationeditors/gallery_relation_editor.qml b/src/qml/editorwidgets/relationeditors/gallery_relation_editor.qml
index f9726e1589..4b6f371626 100644
--- a/src/qml/editorwidgets/relationeditors/gallery_relation_editor.qml
+++ b/src/qml/editorwidgets/relationeditors/gallery_relation_editor.qml
@@ -188,7 +188,7 @@ RelationEditorBase {
     }
 
     onReady: bars => {
-      availableBars[currentProcess] = bars;
+      availableBars[currentProcess] = Array.from(bars);
       availableBarsChanged();
       processQueue();
     }