I can only comment from my direct experience YMMV.
- I have 920Ah of LFP installed in my Class A diesel pusher.
- The batteries are right behind the driver side steer tire.
- The engine is in the rear.
- The wires from the house battery are 2/0.
- They run from the battery compartment to the start battery compartment 30' way, then to the alternator which is another 15'. Total run of 2/0 wire is 2x(30+15) = 90'
- The 2/0 wires have at least 16 ring terminal connections.
- I have a BMK battery monitor installed on the house bank to monitor how much current is being received by the house bank,
- When running with deeply depleted house batteries (-800Ah with resting voltage at 12.5v) the max current received by the LFP batteries was 70Ah with the charging voltage at 13.0v. At the same time, the start battery was receiving 14.4v so there was a 1.4v drop in the 2/0 wire.
- Per ohms law, this indicates that the resistance in my wiring from the alternator to the house bank was 1.4v/70A = 0.02ohms.
- I found the alternator to be no hotter than any other component in the engine compartment.
I have no worries that I am over working the alternator because the resistance in the wiring limits the output current to a reasonable level given the 190A output of the alternator.
That said, this is my experience and if I had a gas rig with the house batteries close to the alternator, I would most likely need a different solution. In that case I would install a Li-BIM 225 which opens the circuit to the FLP for a percentage of the time to allow it to cool.