Custom 3D skin geometry

I've been using this bug since version 1.2
I report this bug because I don't want it to be exploited to make itself invisible or even completely different shapes than the normal skin.
It works on Windows 10 (as shown in the video below) and on Poket Edition, where you also have to exchange the Vanilla folder in the Skinpack folder for the custom skinpack.
Please fix this as soon as possible.

https://youtu.be/-hSl6dsycxk