Min- xcellent thread, as usual!
I have thought of this myself, as you say, just in case.
Although I agree with most that I consider they [the elders] have no authority any longer in my life- but I would not consider it giving my power away to them by acknowledging the request. Rather, my concern as a successful 'fader' would be at this point to maintain that status if possible. Not due to considering that being Df'd or not being Df'd really means anything to me - it doesn't. But it does mean something to some persons that I love and might on occasion wish to associate with. So from that perspective I do care. At least at this point.
If it appears that Df'ing will happen to me - then I would do this; I would tell the elders nothing about how I think or what I know about the 'truth' at this point. I would delay for a couple weeks, stating that I might prefer to DA myself, that I need to give that some thought, and would like to prepare a letter to the BOE to that effect. Set up a date to do so with the JC, shake hands to maintain the peace and to keep them from DA'ing me until they get the letter. Then write a letter to all the persons I love in the congregation, stating tactfully [to prevent it from just hitting the trashcan before they read it] that I have discovered some things that I cannot ignore, confirmed them, and have now elected to withdraw and serve God privately, and remain Christian. I would state heartfelt regret that the organization feels a need to put me out due to my use of conscience, but that is what it seems will happen, and I wanted them to know before any announcement is made in the KH. Restate my friendship with the person individually, and let them know that should any doubts arise [better wording than that I suppose] I would welcome them to my home and life at any time. I understand that as witnesses they will feel obliged to 'shun' me, but hope that they recognize that such is not really deserved when one leaves due to a crisis of conscience.
I would then send those letters and do all I could to delay or postpone the JC meeting. If they go ahead and DF me I would have covered the bases I wanted to, and hope that good human qualities of those I know and love will eventually cause some to knock at my door, and I could share the 'truth about the truth' with them.
Jeff