Looks cool 🙂
If you make the checker more subtle (greyscale values closer together, rather than black/white) then you can get a sense for the more subtle detail, as well as the being able to visualize any stretching/pinching using the texture.
looks like you're losing some volume here, the silhouette is getting broken possibly by missed collisions. Or perhaps you need to go back to the muscles and check if the shapes are right there.
getting some stretching as that limb goes back, it then pops back.
General note - not seeing a huge amount of muscle definition coming through in the skin. May need a higher resolution tet mesh.
Bone rig note:
The way the scapula pivots "out" seems to not be quite natural. I'd have to look at some reference. But seems to be creating a void as it pivots away from the rib cage.
Nice start! Is this with a coupled cloth sim on top?