The impostor for my avatar seemingly generates with an extra lower body (unrigged body mesh?) attached to it, no such mesh exists in the editor.
I will also note that I'm using both VRCFury and d4rkAvatarOptimizer (but it looks fine on the non-impostor version so I'm not quite sure what's going on here)
Avatar ID: avtr_bae0cbe0-847c-4e3b-ad39-dad5be7b8503