@Timo *****
*IF* for whatever reason, the 60 day extension of stay based on unable to travel due to COVID-19 is denied, you would get an "extension of stay denied" stamp. You will have 7 days to leave Thailand after you receive that stamp.
I have NEVER, EVER heard of *ANYONE* getting rejected for a 60 day extension of stay based on unable to travel due to COVID-19.