I would not make this change in advance. If by some chance you do arrive early, CBP is a breeze, you have not missedd B6's bag drop and are certain that you can make it to the B6 gate, then it is worth asking whether B6 will do it for you. If there is space, an agent is willing, and you are ready to go, you may have some luck. Airport agents will sometimes do things which phone agents won't do.
I would absolutely avoid using jargon. This change is not SDC, it is simply a ticket change in which the agent would reissue and collect the fee plus fare difference but, in this case, waive the add/collect. So, simply ask if the agent can get you on the 23:00 flight.