There’s a few steps you need to do before you can get married. Check the U.K. in Thailand page by the British embassy. There’s a bit of running around in Bangkok to do before you can go to the Amphur office. You’ll need an affirmation of freedom to marry. That needs to be translated into Thai and stamped by the Thai MFA.
Apply for a new extension, and buy a re-entry permit, Go to Scotland, come back on the re-entry permit, go through whatever quarantine procedures are in place then. Job done.
Surely she doesn’t have to wait until he 8th of April? Worth going to immigration and asking them if she can sort something out before the March 30th deadline.
I imagine it's because that's a more normal progression. People who work retire from that work. People who have already retired tend not to go back to work.
Why would you want to do that? You will be standing in the immigration office in Chiang Mai when you cancel your Ed extension. Why would you want to fly to Bangkok and then schlep all the way out to immigration to do what you could have done when you were already at CM immigration?