I do the same. BBL for inward FTT and removed immediately to SCB due to BBL insider scam withdrawals a few years ago. However I do it online. Takes seconds and require no verification.
and you confuse people also. You can only get an OA overseas. You apply for extension in country. Renewal after that remains on OA and not O. To convert OA to O the initial visa has to lapse and you apply afresh in country with your bank account. OA requires insurance. O does not.
It’s not difficult to understand. It says to apply “in Thailand”. Of course you need a bank account here. They can not assess your account overseas. If your bank account is overseas then you apply there. Once you have a visa you can apply for bank account. If your visa lapses you can apply again in Thailand because you already have a bank account.