@Stephen ********
it makes sense. Arrive on a 90-days Non-Imm-O visa, you get stamped in for a 90-days stay permit. Get the bank account opened. Then actually you can holiday outside of Thailand. You can theoretically buy a single re-entry permit for 1000 THB for the intial 90-days stay permit as this would keep these 90 days alive, yet it would only make sense if your plans include more days in Thailand until this 90 days stay permit expires. If you like to stay longer, then just exit Thailand, do your holidays abroad and re-enter Thailand visa exempt, which would get you a 60-days stay permit. For this visa-exempt entry I would make sure I got the three famous proofs at hand in case I get questioned at the entry point (onward travel, cash 20,000 THB and proof of acomodation)