Report from Chiang Rai Immigration:
The 2nd Covid extension was valid until 28th Feb.
Applied today for the 3rd (and supposedly last) extension.
Got 'under consideration' - come back 15th March. Extension will be until 30th April.
TLDR : Answer Summary
A user reported from Chiang Rai Immigration that they applied for their third Covid-related visa extension, which is under consideration and expected to last until 30th April, after the previous extension expired on 28th February.