@Garrett **********
Actually, generally you do. There are individual branches who will bend the rules, but the general rule is a non-Imm visa with WP - SCB were bastards about that years ago, but when I went in with a Thai, all magically was OK.
It all depends on your relationship with the bank branch, tbh. I knew an assistant manager quite well at my local Kasikorn. She spoke excellent English and we chatted every time I came. I managed to sweet talk her into opening an account for an ancient old guy who spent 6 months of the year in Thailand but it is all at the manager's discretion.