That was the first few months when Thailand opened up last year, it’s no longer the case but would check with your specific hotel about any requirements if any
I’m in Surat thani, I try to avoid Bangkok during my extension/Covid extension. But maybe someone else can give you a suggestion, I think you can also ask to take a picture of the info you need for a tm.30 from the hotel
I’ve only gone for 2 extensions, one last year and one this year and they have filed for me. But also a good and valid point for my suggestion, go stay at a nice place for a night.
as my understanding and experience is when you book a hotel they file a tm.30 for you so you could go spend a day or two in a hotel near an immigration office you want to apply at and it should suffice