Quoted from Durzel:
I'll probably end up doing this, but at the moment the only things using 12v in my TZ are - as far as I know - ColorDMD, a TV mod and this gumball light mod. Everything else is either clipped on or connected via Molex plugs in series with inserts, GI, etc.
I've already done something similar to what you're suggesting on my TAF using a mod power board supplied by a guy here in the UK:
Plus the opto boards, and the 8-Driver board. There's a LOT of draw on that power board back there. Tax it as LEAST AS POSSIBLE.