Well, just to follow up:

Solved my issue by another route.

The shapes I wanted to split were under an IK armature, so my initial guess was that to edit them, I'd first have to convert the sequence to frame-by-frame, then go deleting the unwanted shaped one by one...

I did manage however, to edit the shape while it still had the armature, and was able to delete the vertices that made up the portions I wanted gone... Wasn't really easy, as for some reason a few vertices decided they didn't want to die, and resisted being deleted... I managed to isolate them and now they don't appear anymore... I assume that after conversion to frame-by-frame those microscopic single-vertex shapes get smoothed out, so it wasn't a problem.


Anyways, the issue is kinda moot right now, but I'd still like to see if anyone knows how to do this... so feel free to reply with ideas/kludges

Cheers