OX was only really doable from the Sydney consulate as it was the only one in the world where you didn’t have to prove 3m in a Thai bank account. No idea if it’s still the same since they’ve changed to evisa.
There is no requirement to have a bank account in the province you’re applying for a visa/extension. There probably would be a need for a TM30 for that province but as we know nothing about what they are trying to do it’s hard to advise.