Was not gate-checking the bags an option? One of my friends told me he has done that a few times, when he was too late for checking his suitcase. Of course, he also told me one of these times the ticket agent followed him all the way to the security line, constantly telling him "you can't do that, you can't do that", and even told the TSA agent not to let my friend through. They let him through anyway, and the gate agent had no problem doing the gate check for him.

About voluntary separation, I've signed voluntary separation waivers MANY times since 9/11, but that was for an exceptionally long lay-over at the airport (HNL) where I wanted to go sight-seeing without lugging my bags with me, and not to fly on a different plane than my bags. Of course, in my case the ticket agent would always start off by telling me "you can't do that", then I calmly tell her I've done it many times before, please give me the voluntary separation waiver to sign. Then they always produce the form and I sign it, no problem.