BulletHead
Adventurer
Because 4/0 gauge is massive, cumbersome, cost-prohibitive, and overkill for the majority of people's needs.
And while the manufacturer may recommend 4/0 cable to meet maximum specs of 500 amps continuous duty... much smaller cable will suffice for almost everything an off-road or expedition rig will need. You would have to use a very large winch with a completely dead starting battery and manually combine the two batteries to reach the limitation of the 2 AWG.
I am absolutely happy to build a kit out of 4/0 cable if that is what is desired. The cable material cost will be approx. 3 times the 2 awg.
You miss my point. Someone could get misled by thinking this kit is designed to carry a load of 500A continuous could get in trouble very quick using that 2 AWG cable. Either reduce the relay load size or increase the cable size adequately to handle the advertised 500A load. Safety first.
FYI, any winch with 9500 lb rating will be at ~500A at full load.