I used it two weeks ago and it said visit the office too. I think they have too many key fields in the data matching. Anyway it is pretty useless. It has never worked.
I would get vaccinated and head to Phuket. You save two weeks in setting up your banking etc and don't have the heavy quarantine. You can move your home bank later.
The TM28 is somewhat obsolete but is easy and can show due dilagence when dealing with lazy landlords. For a family arrangement like this, plan on getting a yellow book. It sidesteps residency questions.
As it opens up, vaccinations will be required. That was more the point. I have no idea about foreign entry requirements. The COEs wil certainly put a stop to the perenial border runs though.