If you're a pilot, and you get bumped at the gate due to weight restriction, ask the gate agent if you can speak with the captain directly. I was in GRU (Brazil) last November. We were told the flight is weight restricted and no more non/revs would be cleared. I asked the gate agent if I can go down and speak with the captain , and I was allowed. I told the captain the situation and he made a few phone calls, a few numbers were changed and I, along with 3 other non-revs were able to board.

Granted, this doesn't always work but most pilots are happy to help non-revs, especially pilots, as long as it can be done within a reasonable time.

Be extremely professional if you're going to do this. The first challenge is to convince the gate agent to let you go down the jet bridge. Once you're down there, chances are the captain will help you