I've just about answered my own question because the supplied compressor power cable won't reach the main battery but I'd like to know if there is any reason to not wire it to the Aux battery? I'll coil the excess wire up between the battery and the firewall, there's plenty of room there. I can't think of a good reason not to use the Aux battery.
Sounds good. I didn't quite finish the wiring. Soldering ends on battery cable takes a while even with a 150W soldering iron. While I had the glovebox out for routing an amp bypass wiring harness I pulled in the ARB switch wiring and pulled the dual battery controller wiring wiring out from the cab to the engine compartment. I used an awl to punch a hole in the grommet in the firewall. Push a coat hanger through about 1/2 way. Taped the ARB switch wiring to the coat hanger wire about midway, pulled in the wire into the LC, untaped the wire from the coat hanger, taped the ARB wire to the end of the coat hanger, and pulled that back through. Worked like a charm.
