Interesting, I hadn't heard of that website in ages....
I clicked on the website and they said you cannot use e-visa if you are a US citizen resident in Vietnam....
HOWEVER, the website also popped up a message saying that as of 26 SEP 2021 (yes, 2 days ago), they have FINALLY fixed the fundamentally broken e-visa system so that it is no longer necessary to submit one's passport to the local embassy/consulate as part of the process (which, of course, COMPLETELY defeats the whole purpose of being an e-visa).
Instead, finally, the e-visa website ends up in you getting a confirmation e-mail which you print and present to Immigration at the border along with your passport.
If that's really true, it is a massive sea change to the Thai Visa process and it would mean I could apply from anywhere. I'm surprised it's not major major news on thaivisa.com, I mean aseannow.com
Is it really true?? Is there some "TIT" catch?