The click trick...

Hhhhmmmmmm, interesting predicament Captain, and one I might have a logical solution for? I think if you go into System Parameters, you can assign the metronome to MIDI Ch.xx? (It's no doubt preset on Ch.10?), and/or set the metronome to play REC, REC/PLAY, ALWAYS. (Highlight REC and rotate dial)
So I'd recommend to set to ALWAYS, get a cheap MU Tone Generator box (MU10 etc.), MIDI OUT from 808 to MU10 and drummer uses headphone jack, and mute or turn metronome volume down to 0 on 808. Now if you Tap Tempo while auditioning/playing a sample the drummer can also get the tempo as well to start the piece.

My Vulcan logic Captain.