Does $dc_observers.get_latest_class.redraw_with_undo(instance) only work with Sketchup::ComponentInstance?

Redraw should work on groups or components. Can you post your code?

EDIT: Group attributes are kept in the definition instance, where components have attributes at the instance and definition level, this is likely probably not your issue… :man_shrugging: You have to set the group attribute at the definition instance.

EDIT2: I had it backwards, corrected above. Thanks @DanRathbun!