YMMV, but in my experience, they're actually pretty liberal (believe it or not) w/carry on, as long as you don't put your oversize right in front of their noses. Just keep it down below or behind you. I bring a way oversized backpack & a daypack all the time and never have had a problem. I just waltz through like nothing's wrong. I see many others way oversized or 2 items as well. Since you're checking so much already, & they have to get involved, they may try to stick you though.