I learned a lot wiring boats. First off, run the largest gauge primary wire that will make the bends required to install. Thinking is you are making a sacrifice to the corrosion gods. Second, you always run grounds in boats, I do the same on trucks.
#1 issue I run into with Toyota electric is grounding. When I swap a truck part of the package are all new battery cables.
Grounds-Body next to battery, Frame, Engine block, Radiator, Block to fire wall
Dedicated ground back to battery for fuel pump
Dedicated ground Batt to Bus panel in...