Larger boats have this same issue - that is; the current to pull in the starter solenoid is lost in the wiring harness since it is a substantial amount. Then (with the boat with a flying bridge) the distance, switch contacts - it becomes very inefficient. Boat starter wiring therefore always includes this auxiliary starter relay wired back at the engines so the current through the starter switch can be reduced to milliamps, thus less loss in the wiring - ohms law....
Boats: bottomless pits in the water to pour mucho money... the only similarity to a CUT is wiring, switches, relays, batteries, safety switches, solenoids, starters, engines, and maintenance - but only one wheel.
BillC