Hello @Pierrot and @fakemoth 
Two questions for you below
This Sep 18th update from Virtualmin staff might be of interest at When will Debian 11 be supported? - #2 by Joe
The good news is they are planning to support Debian 11. But they will not pre-announce a date for Debian 11 support. I agree with their choice. As it was repeatedly was successful in the past.
Same here. I’m looking forward to Debian 11 support, though. Speaking for myself only, as volunteer, to contribute to potentially speed up this goal, I’m happy to offer testing and documentation. If any are both needed & expressed.
EDIT BELOW :
Question 1: How about you? Are you interested to contribute volunteer services toward potentially speed up reaching this goal?
Question 2: If yes, what are you interested to contribute?