Add a cache for settable_per_extruder property

cura/Settings/CuraContainerStack.py

@@ -60,6 +60,8 @@ class CuraContainerStack(ContainerStack):
         import cura.CuraApplication #Here to prevent circular imports.
         self.setMetaDataEntry("setting_version", cura.CuraApplication.CuraApplication.SettingVersion)
 
+        self._settable_per_extruder_cache = {}
+
         self.setDirty(False)
 
     # This is emitted whenever the containersChanged signal from the ContainerStack base class is emitted.
@@ -387,6 +389,16 @@ class CuraContainerStack(ContainerStack):
             value = int(Application.getInstance().getMachineManager().defaultExtruderPosition)
         return value
 
+    def getProperty(self, key: str, property_name: str, context = None) -> Any:
+        if property_name == "settable_per_extruder":
+            # Setable per extruder isn't a value that can ever change. So once we requested it once, we can just keep
+            # that in memory.
+            if key not in self._settable_per_extruder_cache:
+                self._settable_per_extruder_cache[key] = super().getProperty(key, property_name, context)
+            return self._settable_per_extruder_cache[key]
+
+        return super().getProperty(key, property_name, context)
+
 
 class _ContainerIndexes:
     """Private helper class to keep track of container positions and their types."""

cura/Settings/GlobalStack.py

@@ -192,7 +192,7 @@ class GlobalStack(CuraContainerStack):
         self._extruders[position] = extruder
         self.extrudersChanged.emit()
         Logger.log("i", "Extruder[%s] added to [%s] at position [%s]", extruder.id, self.id, position)
-    
+
     @override(ContainerStack)
     def getProperty(self, key: str, property_name: str, context: Optional[PropertyEvaluationContext] = None) -> Any:
         """Overridden from ContainerStack