Phetburi today changed their tone by saying they were unsure if HQ would approve and that my husband would have to leave Thailand in 7 days if rejection was the case, as this was his first extension. Donno if the advice was 100% correct but we are sticking with the existing reason/basis which is retirement, as a result.
BTW THEY were the ppl who kept advising we could switch reason.
Sorry. I thought our experience might be relevant or useful to the OP, I did not mean to cause any upset or confusion.
Phetchaburi Imm Office said a few months ago that they would allow my husband's O-A extension based on marriage. This is the first extension as well. The boss there said to me only a week ago that this would be down the Imm HQ in Bkk, something nobody told us before. Such reassurance!