From reading the forum posts it sounds like you have a bit of a head start on me wrt electrical knowledge!
I have wired a plug and changed a fuse, changed a light fitting, and built my own PC I guess.
Setting aside my dubious practical skills for now...
Is 100% DIY feasible and still be able to export to grid when starting a whole new PV system from scratch?
Assuming an ac coupled system, at the very least I'd need to find a friendly electrician to connect the PV/battery output into the house side of the consumer unit (?) and would be best involving them from square one with the system plans?
Building my own battery might be doable if I were to devote all my spare time and get some serious safety advice on working procedures.
Wiring up a quattro, a 450/200, PV cables, isolators, cerbo gx, etc. and assoc. gubbins feels like a mountain, ... ok one step at a time i guess.
And then when it don't work 1st time, where's the help with problem diagnosis, do victron support DIY installers, I suspect not.
I can appreciate the sentiment, McEnroe's words to the umpire come to mind though?!
Hmm should prob make this a new thread.