Brook wireless fighting board dual mod

Has anybody added a brook wireless to a multi-PCB setup?

Playing around with one this morning I noticed that battery does not provide voltage over the vcc and gnd pins on the screw terminals or the 20-pin header. It only provides power for this board.

I’m wondering if this fact effects multi-PCB setups.

I know the cardinal rule is all pcbs must be powered at all times but I also know this is not necessarily the case in all situations just very good advice.

I just posted this, specifically dual modding the wfb with a retro board: