By Adam Nagy
If you need to check if the model got modified since a certain point in time, then you could use the value of ModelGeometryVersion property of PartComponentDefinition.
This property is updated with a different value every time there’s a model change. This includes sketch changes and is for the entire part, not specific bodies.
All component definitions have this property: AssemblyComponentDefinition, SheetMetalComponentDefinition, VirtualComponentDefinition, WeldmentComponentDefinition, WeldsComponentDefinition and so does FlatPattern.