My plane lands at 12:05
I get tested at 18:00 at the hotel in Bangkok
The result is due by 14:00 next day and I've seen evidence of someone else getting the result by 13:00 in the same hotel.

This seems to be slow, however at least I have a nice room in a well reviewed hotel.

I'd rather be out by 8:00~9:00 am, but to exercise my rights to free cancellation for the quarantine hotel, I'd need to identify a genuinely better alternative AND be confident that the Thai Pass would be processed promptly.