Without going on too long a tangent, this hasn't been our experience in practice at NoRedInk. We've built some absurdly complex UIs involving those same design

Without going on too long a tangent, this hasn't been our experience in practice at NoRedInk. We've built some absurdly complex UIs involving those same design needs, and what you're describing just has not been a problem. I'd suggest giving it a try. It's really nice. :)