[IlludiumQ36]

An added shunt would work counter to a wire gauge decrease( larger diameter wire... don't ask me). You'd be adding back in the resistance you had been trying to remove with the wire change. The main difference would be that the heat generation would be at a point & could be easily disipated into a hunk-o-metal. It would be a trade. Me, I'd do it. Then again, I did this so I could get a needle to move.

Rethinking that, Yes. I forgot that this path was only for charging the battery & discharging when alternator nor running/working. I think that would be a viable solution, I'd expect that folks really did not need the increased diameter wire here in the first place but in the alternator out to the loads direction.

I don't expect that prolonged < 1A would be a real heat generator so I don't think it would be an issue, that said, I did decide to cut my added resistance in half just for that reason.