Keynote Presenter view - on a third monitor instead of the primary?

I have what will probably seem like a bizarre request - I have a Mac Mini with three monitors that I use for presenting in our church. The primary display with the title bar is the "operator console" for whoever is driving the mac. The second "monitor" for the Mini is for the projectors up front. But we also have a "third" monitor for a screen at the rear of the room that is for whomever is on stage - a "stage display" if you will.

I would like to be able to tell Keynote to put the presenter view on that third display, and not the primary display. The preferences in Keynote let you change around the primary/secondary monitor, but they don't seem to factor in that you could have more than two monitors.

I'm hoping I'm just looking at this with a narrow vision and I'm either missing something obvious or there might be some other trick out there to accomplish what I need. Unfortunately I can't do things like mirror the 1st and 3rd monitors since I can't take time to reconfigure the video setup since our primary presentation software (ProPresenter from renewedvision.com) takes advantage of all three "monitors" - ideally I need to be able to figure out how to make Keynote work with the configuration we have.