Cool. I think I'll just tell anyway. I'm not too overly interested in the subterfuge of it all. I just care mostly about confirming that it *would* work, that's good enough trophy for me.
"Withdrawing" isn't a regulated action apparently (note that I, as the initiator, am not required to track any Objections until I actually intend to complete it, when I need to publish the list, I believe). Or it is, and since there is no explicit way to do it, nobody can actually withdraw, ever. So I can just do the unregulated action of "I withdraw your objection" (would my proof of "all actions are regulation actions or not actions" not work)