Hell, she's close enough in appearance (and we're dealing with a magical gamma-powered body transformation) that they should have just given up on Maslany in motion capture and used Arrayah for all the She-Hulk stuff.  If Arrayah's a decent actress, they might not even have had to use Maslany for a lot of the facial reference.

Putting a petite actress on apple boxes just isn't the same, and there's only so much CGI can do to make all those body parts realistically move and interact with a physical environment when the actors can't see them during their physical performances.