You should be ok on the Roll-Over Valve.
ROV system only draws approx 20-30 milliamps (just enough to power the ROV relay) while the engine is running.
With key on/engine off and tether pulled (ROV closed), current draw is just 300-350 (approx 1/3 amp) for the premium kit with a ROVCM.
Valve closed current draw for the standard kit is 500-600 milliamps (approx 1/2 amp).
Bill