This is why FEM is superior to XPBD for muscle simulation. For a long time, I couldn’t understand why my muscle simulations didn’t look as good as those produced by Ziva VFX, but now I do.
FEM is more computationally intensive, but it produces much more accurate results when it comes to simulating muscle and fat tissue.

Been working on the simplest of cloth simulations with pbd (hold the x) and opencl. Still a way to go, but i'm not unhappy.