>>2845708Here's a vid to give you an idea on how the BDEF4 bottom is set up in my model:
https://files.catbox.moe/xxi238.mp4It's not that hard in practice, what's hard is preventing cloth clipping around the middle of the rear—you can't just transfer vertex data in Blender and call it done unless you already have a flattened preset mesh without a butt crack to copy weights from. Alternatively, you can weigh the ass entirely to lower torso, maybe with ass jiggle weights thrown in, and only start leg weights below the buttocks. The HK base (e.g.: HK03_v01e) does something like that.