Perhaps I'm in the wrong thread but there is no part of me that wants to DIY my own power electronics design. I've designed a few bucks and boosts professionally and chasing down those failure modes was a headache. Victron = solid hardware, openly-documented protocols, no cloud? Fahgettaboudit.

(then again maybe someday I'll hit some wall with off the shelf MPPTs and find myself wanting to go down that rabbit hole lolol. but honestly AC coupling seems cleaner in terms of things like fault protection on longer runs - fault on a stiff mains circuit -> breaker will trip. Fault on a circuit where the current/power is intrinsically limited to what the solar panels can supply -> ???)

I asked about the transfer switch / monitoring because I've looked at the same problem here, first with a generator now with solar. Incoming power service is on the complete opposite side of the house from where I really want the power handling gear. The manual two breaker thing is practical (for a generator at least), but not code compliant here (no positive lockout).

I would think Victron would have an option for a remote transfer (/disconnect) switch, but I haven't really looked into it yet. It would still have to get the grid phase timing somehow to line them up before connecting, so something more than merely a dumb contactor.