Thanks a lot, that sure does help a bit. I think I will ponder the options before rushing to any conclusions.
There is one thing, however, that might deserve mentioning now already, and that would be the transfer procedure of the existing visa to a new passport (if it so plays out). I found
https://ltr.boi.go.th/page/transferring.html
which appears exhaustive, but upon closer inspection still leaves some doubt (transferrable stamp, being my case):
1. They mention a One Stop Service Center for Visa and Work Permit (OSS), but would fx Pattaya immigration also be authorised for this business?
2. They also enumerate three documents that I do not expect to obtain, or do not in necessary detail know what they mean:
- Certificate from embassy (Original one only)
- Notification letter of qualification endorsement which is addressed to the Immigration Bureau
- 1-Year notification card
Next to this top-rated private website, there's also seemingly official info available at
https://www.thailand.go.th/issue-focus-detail/002_005
But it does not appear free from doubt either.
I'm puzzled. Any ideas how to sort this conundrum?