I wasn't satisfied with movement of arms so I tried various systems to have a good arm deformation. I ended up using a muscle system, so I have to find all the insertion points of the muscles and somehow build a muscle structure. This is good because the experience I am doing will also be used to do the various vintologi trannies.
The anus of this human female is deformed using physics. The tits have a bouncing tits physics that reacts to collision. The anus stretcher mechanism works properly. The pussy deformation is achieved through simple shapekeys. Stomach bulge deform is achieved using a boolean operation to and then wrapping deform bones on the boolean, this is to simulate "contact" with the shapes that touch inner surfaces of this mesh.
This muscle system is redundant, but I wanted to do very extreme hentai poses, normally a custom rig would to the job, but not in my situation.
Hair shapes are particle systems, they react to physics. I have to decide how to do the cheatcodes (makeup), best results are achieved thanks to particles.