Personally I would say it’s more convenient to apply for the initial 90 days Non O visa before you come and apply for the one year extension of stay in Thailand.
This was my personal experience at the Krungthai bank in Buriram, same branch as I opened on visa exemption previously;
Tried to open a second savings account in Krungthai bank last month with a Non O visa. They didn’t allow me even if I’ve been a customer in their bank for 11 years with a debit account and could provide a residence certificate. Requested a yellow book or a work permit as well.
They referred to general written guidelines from their head office and gave me a copy.
If you’re on a 60 days visa exemption and able to open a bank account by yourself only by purchasing an insurance your can cancel after a year I would say it’s worth it. I just got denied in one bank with a Non O and an agent wouldn’t be any cheaper anyway.
Tried to open a second savings account in Krungthai bank last month with a Non O visa. They didn’t allow me even if I’ve been a customer in their bank for 11 years with a debit account and could provide a residence certificate. Requested a yellow book or a work permit as well.
They referred to general written guidelines from their head office and gave me a copy.
Yes that’s an option, but then you’re not using your Non O-A for more than a two years stay, and I’m not sure I would have use the mandatory health insurance for more than two years either. Probably better to get a regular Non O and fulfill the requirements at once to get a more permanent stay if that’s your intension in the first place.