you get different stories but figured out you DO still need to do the 90 day report ( don’t forget to ask your first hotel or landlord to advise the TM30 when you first arrive otherwise 800 baht fine like I had) and then at the year you should prove you have the funds in your account 3 min or 1.5 min with a minimum pension or support of I think 75k per month. I have not got there yet nor have I transferred any cash and going back to the UK for 6 months but will figure that one out later.
I have a non immigrant OX for 5 years and in Thailand. I am 63 so not retired but also not working. Retirement visa has less requirements for cash in the Bank.
I have OX and you still end up doing 90 reporting etc but you can open a bank account with it if you have a permanent address (not hotel). Then you should transfer money within 1 year to the account as they like you to report annually. Better to go for a visa that requires the least in a bank account as you don’t really want that much cash tied up doing nothing, especially if the baht weakens.