Another option is O-A visa, your financial requirements are UK based, £20,000 in a UK account for 1 month but you will require a police check - a DBS is £18 and takes about a week; Medical certificate (see link for requirements
-non-immigrant-visas); 100,000 USD insurance from specific providers. AXA is a cheap bare bones policy which will suffice for visa.
With this visa, you can potentially get 2 years from it. Your first year is multiple entry, when you arrive you are stamped in to the end of your insurance (so make sure it starts the day you arrive). If you exit and re-enter before the visa expiry date, with a new 12 months insurance, you will be granted another year stay. The 2nd year is not multi-entry but you can buy a single or multi re-entry permit in Thailand.
It does have its costs with the insurance but if you want to have the least contact with your local immigration, it's a good option. It's exactly why I have it, as my immigration office are difficult.
I'm aware of the rules and it's not affecting me. I was trying to help the OP. I'm with SCB, I get additional charges receiving over 50k, so I just send 49,999 when I need it.
I was reading on a forum the other day about it, some Bangkok Bank customers using Wise were getting these additional information requests for transfers over 50,000 baht. They were all US customers, one mentioned he sent 49,000 and it went through okay. There were other USA customers trying to help who were not having this problem. Not sure what the conclusion was and I can't remember what forum it was on, I've just had a quick look on Google with no luck, so it was probably a Facebook group.
Anything over 49,999 baht seems to cause problems these days due to anti money laundering. I just do 49,999 a time and I use Currency fair. Wise seems to take longer to SCB. I have done over 50k successfully but it took over a week and there were additional charges.
O-A visa can only be obtained in your own country and requires 100,000 USD insurance. I flew from UK with EVA and the Thai man at the airport took our evisa and insurance documents to check. Now, whether they check this against immigration records or not, I don't know. The evisa states you have insurance but he still wanted to see the insurance document.