i thought i recalled something in the MP that does fixes other than the Perfect Vicky ones. [it] took some time to find, and it doesn't address the arse issue [though maybe this vendor has other fixes, as i just grabbed the first pack i ran across], but it looks like it does something to the hands... shrug...

https://www.renderosity.com/mod/bcs/?ViewProduct=99590

i'm one of those that just tries to do fixes and such in Photoshop, so i can't offer you much advice regarding the brush in Poser, but it does sound like, if you're unhappy with preset fix packages, that either you'll need to learn more about the brush, or further your skillset within Photoshop...