When I added ClothSkin support, I noticed that the method I used to 'hide' parts of the skin left some gaps when simulated. In order to fix that I played around with different ways to do that. Unfortunately, they ended up corrupting the mesh and causing issues for some people.
This change reverts things back to what the process was before, but as a result AltFuta might have gaps in places when used with ClothSkin. I'll try to fix it in a later update.