SCB are very strict now for account opening. They have big silly book of what acceptable ID looks like, and zero ability to reason beyond what the big book of A, B,Cs say. For example even though I'm married and staying on extension, they wanted to see the NON-IMM O full page visa affixed to the passport as indicated in the big book of A, B, Cs, no amount of explaining extensions and arriving on e-visas would be accepted, the big book of A, B, Cs doesn't cover e-visas and/or extensions of stay. I argued the toss with them until the manager said I can apply for an exemption from head office and if they say what you have is okay I can open an account, will take 2-3 days, at the point it felt like a small victory, so said cheers, but nah, and walked across the road and opened a KBank account in literally less than 20mins.
You can always give it a try, but I suspect based on the big book you'll have to wait until you have your non-imm B affixed to your passport and/or work permit.