hrvoje_hr I didn't want to fork this plugin so I decided to replace some code by myself for my forum. It's a bit complicated but I think it could be interesting to share. I replaced sorting default options by mine.
For instance, open src/content/UserDirectory.php and replace :
'newest' => '-joinedAt',
'oldest' => 'joinedAt',
'most_discussions' => '-discussionCount',
'least_discussions' => 'discussionCount',
by
'newest' => '-joinedAt',
'oldest' => '-lastSeenAt',
'most_discussions' => '-discussionCount',
'least_discussions' => '-commentCount',
I had to replace the same 'joinedat' entry with '-lastSeenAt' and 'discussionCount' by '-commentCount' in js/dist/forum.js and js/dist/admin.js . Reload cache.
Then I had to change translation of entries in list to display correctly.
BUT CAREFUL !!! It works only for registered users, so I had to disable the plugin for non registered users !