I agree and like the toggle's manual simplicity Rob but I guess the BPC module advantages changeover from TPC to ZW via the handheld Cab 1[or 2].
I have a couple of BPCs stored somewhere from a dismantled layout. I used them to temporarily switch power[via Cab 1] to a single transformer source when my engine pickups were in separate districts upon crossing over the center rail gap between the two districts or tracks].