To answer a couple of your questions that I don’t think have been addressed….yes, the work legally MUST be permitted and done by a licensed contractor. In CA, legally, there is no such thing as an unlicensed contractor. If they call themselves a “contractor”, by law, they must be licensed. I once won a double small claims suit against a seller and broker for unpermitted work done by unlicensed handyman, when the purchase contract called for it to be done by “a contractor”. It was also related to the termite inspection. Coincidentally, the bid provided with the inspection report was right around $20K. Seller had the work done for $1,200. And never paid the schmuck who did the work.