Another one I just thought of here: option for 'time range', so that an animation will start from Y Ma and play to Z Ma (e.g. 50 Ma to 20 Ma, instead of full 250-0).
GPlates has a 'configure animation' dialogue, so basically would want most (all?) of the options there. 'Reverse animation' would be good too imo.
https://github.com/GPlates/gplates-app/issues/8#issuecomment-1120648666