Chassis erfs and other short cuts are for pufta electrics - turbo boost gauges and panel lights. Don't matter if they fail. A few dunkings in ph 4 bogs will see a fine specimen of electrolytic corrosion on yer connections. The only way to do it if yr serioos is to run yer 35mm copper from bat earth to master cut out relay (450A rating) then to chassis bolt A, then from chassis bolt A to winch. The starter kin also go go from chassi bolt A. I've seen too many elec winches go us in flames (one one occasion while carrying on winching Rangie) not to put in cut out.
Put yr dead cut out switch in earth connection means when you later add all those fings wot you forgot about, and wire them direct to +ve bat, you'll still have master cutoff control.
