The embassy may be shoddy (no problems with LA embassy so far for me) but it’s nothing compared to a shoddy agent in Thailand.
If it were me I would get an O-A from the LA embassy and be good for two years. You would need the insurance, and a clean physical and criminal check though, not sure if your already covered. Big plus is that you don’t need to move funds or have a Thai bank account. Depends if you have a mailing address in the States and would return every two years. You have more control of the situation because your not pressured by dates and stuff expiring.
Anything in the states secured beforehand is easier than dealing with stuff in Thailand after arriving, in my opinion. You’re going to have everything you need, not bopping around town looking for a “reputable agent”, or trying to convince some bank clerk that they deserve your business. Like the saying goes “if you want it done right, do it yourself” has worked great for me so far.