Hey, I saw your post on HF! Unfortunately, it's been giving me issues, so I'll just reply to you here.
I'm not sure if the breast manipulation was fixed yet for the studio (haven't checked, yet), but did you know about the Studio IK Mod/plugin? It has fixes for that, among other things.
I tried tinkering with it, but... I couldn't figure it all out, lol. Dealing with bones, etc., is quite new to me.