Swapping to lithium batteries could be a game-changer, but you'll want to make sure your current setup won't mess with their lifespan. The way you've described your system, it seems like it should work fine with lithium, but it's always good to double-check with the battery manufacturer to be...
Going with the 300Ah LFP battery and Victron Comms seems like a smart move, and the buck-boost for charging from the alternator sounds like a good idea once it's back on track.
Keeping one AGM as a start battery is a good backup plan. Using the 4/0 cable for the distance to the Lynx makes...
Your setup sounds awesome! Adding more panels and batteries sounds like a great idea. As for staying on NEM 2.0, adding <10% / 1kW should be doable without needing a whole new plan set, AHJ, or PGE inspection, but it's always a good idea to double-check. Off-grid could be a practical way to...