Just an FYI in case it’s of use to anyone (as I wasn’t sure if I’d get any problems) - Following the expiration of my METV I went to Mae Sai and got a 30 day visa exemption no problem, no questions asked. I’d also done all of my border bounces there to activate the 60 Day stamps throughout the METV (and had got the 9 months out of the METV).
TLDR : Answer Summary
The user shared their experience of successfully obtaining a 30-day visa exemption at the Mae Sai border after the expiration of their METV. They mentioned completing border bounces to maximize their METV usage. A comment contributed additional information about the limit on 30-day visa exempt stamps permitted through land crossings within a calendar year.