Rebounding isn't as bad as it appears IMO. It's easy to just look at the stat sheet and see the offensive boards the other team is gathering but some of that is scheme too. With our help side/trap style of defense it's almost impossible to account for everyone. Our biggest area for improvement is probably on the post. We have a tendency to get a little too deep. We also force teams into taking 3's which lead to long rebounds.
This is dead on and I was just talking about this with a buddy the other day. We do more rotating/scrambling than most teams defensively with our doubles and aggressiveness. "Boxing out" is premised on being in a position with the person you are guarding where you are between them and the basket. With the way we guard, that's often not the case. So I do think we give up some rebounding for our defensive aggressiveness, and I'm fine with that.
The only egregious one I can remember was Keshon not boxing out on that put back in the last minute of regulation. That one was effort. But other than that I think it's just a byproduct of a few bad bounces and a defense that leaves us vulnerable to rebounds.