[notahacker]

I'd either want the deformity testing either integrated with the generation service (really deeply if it's a GAN!) or a post processing tool (a "look, dodgy hands" layer in Photoshop which could then allow you to fix those deformities) rather than a separate web service

If the quality of the model is difficult to replicate (which seems to be a big "if" at the pace of NN image processing improvements), I guess there might be licensing or plugin sale opportunities there