Hey , question for you whenever you get a chance.
I’ve managed to map and replicate your grasping hands onto my full IK mesh, using a custom grip component tied to the palm of the hand, and ripped off your collision capsule and overlap model to great effect. It works a treat, and look darn good doing it - but I can’t for the life of me get both the IK and any sort of physics interactions on the hands.
My first inclination was to use physical animation components and profiles on the mesh, setting all bones below hand_r and hand_l to simulate (everything is mapped to epic skeleton.) seems to have no effect at all - all of the examples I was able to find that used physical animation components were all both 1) not using IK and 2) simulating only below a single bone (generally pelvis) rather than two. could be a general misunderstanding I have about the effect of these components, but I think the conclusion I came to is that since IK is based on evaluating toward a target position, it will always attempt to reach that position regardless of collision. I could be wrong here.
Since I came to the first conclusion, my second inclination was to create a separate mesh for the hands, then simulate those as floating hands and use their (post-physics) position data to inform the IK targeting. However, never matched up perfectly - it seems there is an offset from the pivot of the fully simulated hand mesh and the IK targeting, and I can’t for the life of me get those offsets to match up - meaning I can get it to line up perfectly in one position, and think I have the offset transform all figured out - but then moving still results in misalignment. I think is probably related to the hand’s center of mass being near the palm, whereas the IK target is always the wrist.
I’m a bit lost as to where to go from here, and was wondering if you might have any insight into what I’m trying to do, or if I’m just completely barking up the wrong tree. 
Thank you!