You can add unsupported extensions by using custom add-on collection.
Endrom
joined 2 years ago
I left but logged in to see if my deleted post and comments were restored. Some of them were restored so I edited them to nonsense
I was using K9 for sometime and I liked it but had to switch to fairmail because deleted emails kept reappearing. I dont know if it was K9 bug or not but i don't have such problem with fairmail.
It doesn't really matter if it's usefull for others. Write it for yourself and learn from it. I myself wrote copying script for terminal and I am sure no one else going to use it just me and thats fine.