Hi, really no idea

, I have many (hundreds of feature requests in my fr list which must be solved), for now I am spendig every night with answering posts in the forum which takes a lot of time

(20900 answered posts - this is really not normal) so if community will not help - see:
https://www.phoca.cz/phoca-needs-your-help/ it really takes some time

which I cannot estimate
The idea of selecting each users for category upload right was that every user has own category and implementing user groups rights over this rule will take a lot of time because a lot of code must be overwritten

(there are different rights - category, user, menu link, access, upload, delete, ... which must work together

)
Jan