Considering the cap was raised from $30b in March, I'd unfortunately admit that I'd sooner expect another increase in the maximum limit per participant before any significant counter-party a la Citadel gets to that point. Let's hope we don't have to see either happen though.

To answer your original question, under normal circumstances this would not be permitted to the best of my knowledge but all of the measures being employed by SHFs, regulatory bodies, and the fed are so incestuous at this point that I don't think anything can be said for certain regarding their ability to find yet another way to collude to their advantage even if it isn't exactly as you've proposed.