Hands "ground" and independant movement
There's an option to attach the feet to the ground, but it would be really helpful to have hand controls like that too (to a table, a desk, etc.) so it doesn't go all weebly-wobbly during animation.
Also, having a separate Handle/Behavior for hands would help to follow the movement capture in-cam and help sell the movements and not be only a floppy continuation of the arms.
I saw a lot of problems too with a 3/4 character, arms are suuuper hard to animate. I've change them from already bent to kinda bent and it kinda fixes things, but to get from a file for client approval to animation, it takes times to adjust them so the result is the same. If you can figure something magic out, great (if not, I am probably sure you're doing the best you can).