Wire piezo to zone 6?

I realize the instructions say to use zone 1-5 for the piezo buzzer. But I already wired mine for other sensors. Is there any reason not to use zone 6 ? I have the v2.0 6 zone starter kit alarm board (current model as of Dec 2020).

Never mind. I see now that only 1-5 can supply +3.3VDC.