Since I started the thread and I went today to extend my Non O retirement at Korat immigration.
I'm not trying to be contentious or disagree with all the helpful previous responses but this is what actually happend:
TM 30 (issued 22 November 24) accepted.
Blue ink produced by overlaying in a pdf program on my computer not liked by initial (trainee checkers who help you fill in forms) but not a problem with main checkers and immigration officer (I use this method because I have arthritis in my writing hand and my writing is difficult to read).
STM2 form has changed from last year (as far as I could make out only in so far as two sheets have become double sided) Took the precaution of getting a blank set to scan.
Everyone helpful and friendly to deal with.
One thing to note - two pages on the blue book (the initial page and the page with the owners? name) need to be copied to the same sheet.
Got the extension, 90 day report done, new TM 30 and single re-entry stamp done by the immigration officer all in one go.
Oh yes, Internet went down for an hour or so whilst I was having the stamps put in the passport.
Funnily enough the same happened last year but there is a really nice restaurant just opposite so no sweat 😃.