I plan to follow Steve187 advice, my situation is similar to the OP. I have a business in the UK which I plan to retire from in April 2025 and don't wish to transfer lump sums to Thailand for now. The O-A if used correctly can allow you to stay unto 2yrs in Thailand. I will open a Thai account this year in May and transfer 40,000thb a month from my Wise account for a year this giving me the required funds for immigration requirements for future extensions based on Marriage (400,000 thb or 40,000thb a month).
If you wish to keep your funds in your preferred country you could opt for the 40,000thb a month to your Thai bank which you can set up with the O-A visa.