So I been pretty curious and trying my hand on making some Shapely beautiful booth avatars. And actually all goes well with them, they look good, and are a beauty for sure.
Basic synopsis is I use scale bone on breasts, butt and thighs. And once that is done, they look good in the Unity Work Screen. All look like they fit and all.... However I have some issues which I cant fix nor have any idea.

1. Gogoloco- I use it in all my avatars as I dont have FBT. However due to the increase in the thigh sizes or something, the gogoloco would clip or break the legs. Not break but clipping issues occur behind the knee bone, making it disfigured. The thighs and butt arent my main focus so I can just not edit the bones and should be fine. Though telling would be a good idea and seeing if any solution would exist.

2. Marshmallow??- Unsure if its a Marshmallow issue or something else but even though in the work screen, the avatar looks good and all, when I click the play button, the tits either poke too front of the outfit or drop lower then the top, exposing themselves. It works in some outfits while not working in other outfits. I even changed the Y Bone in Marshmallow to match with it, yet this issues occurs and every outfit is different. I say its a breast issue cause the butt and thighs with the shapely edits, work perfectly. So unsure if I have to remove Marshmallow and replace it with a different breast physic.

If people do say I could on blender, I could but I have no tutorials about it, plus the bounce and jiggle is a module of Marshmallow I think, not of blender, so regardless, it wouldnt work. Any help would be appreciated. Many a thanks!