To be honest, I don't like phpBB.
Especially not for this usecase, as data migration would not be easy or possible.
What I really would like is to have the Drupal updated to the latest version but that is also a big task that needs time and effort and I didn't have enough time to finish this yet.
I think with a newer Drupal version it should be better. This Drupal verison is ages old.

I'm not sure if the forum's platform is that important - of course there should be a proper search. Aside from that, someone has to maintain the forum and maybe it's more important that he feels familiar with the platform. I'm not the one who would maintain the system (no experience at all).

I'd like to see a more useful forum site: There are 9 forums, but 5 are dummies and countless times I've answered "Look at the Mailing List...". That's not news, but it doesn't change...

I agree. Also, all "Developer Discussion" and Feature Request forums are dummies, because the developers almost don't read them. Instead, they are very active at the jEdit Developers Mailing List ( https://lists.sourceforge.net/lists/listinfo/jedit-devel ).

Would You mind to post Your hints and offer to the Mailing List? There has been some discussion and activity regarding the forums some time ago and without visual results. Maybe Your offer could give it a kick.

Good Luck!
Robert