I'm in the same position as you, I have done the non o 90 from Savannakhet since last year and the online appointments are a ball ache. I did get one but it was for last Friday meaning a 6 day stay with the King's holiday plus the weekend.
I scrapped that idea as I'm sure that's the only reason I actually got that appointment as the new ones get grabbed as soon as they are released but the visa run companies no maaltter if you're refreshing the page at midnight or not. Plus spending 6 days there is not my idea of fun.
Anyway I've just done a border bounce to Cambo, Ban Pakkad. The visa fee is 1400 baht but if you want to go out and back same day it's 2700 which I'm told is no issue. I decided as I hadn't been there before to stay the night in one of the casinos and with the hotel, food ect it came to about the same price.
Morning crossing was a breeze, filled out tm6 🤣, went to Thai Imm window, brief look through the many non o stamps I've had, stamped my passport and I was off with a khrap.
I'm thinking I will use them until I get legitimized as my sons dad then I will do the yearly extension route. I haven't done this yet as I can't be bothered going through the courts nonsense and when he's a little older he can say I'm his dad at the Amphoe and I don't need to do this.
This stamp will take me through till January 2025 with the 30 extension plus the 60 to visit him. Next year I'll do the 2 border bounces with extensions plus the extra 60 to visit him for each one which will give me 10 months by which time I will be able to get the yearly and for now I don't mind traveling about as I haven't seen much of the neighboring countries yet and I'll tie it in with a trip to them.