Updates to GitHub will be emailed to the Arduino administrators, so the more comments people make, the more they are likely to think that someone wants things fixed.
Trying to keep a positive slant on things: if you notice forum bugs please ensure they are posted to the arduino/forum-issues/issues/ part of Github ( https://github.com/arduino/forum-issues/issues/ ). Check if problems already exist. If not, add them.
The irony is, they will probably not read that suggestion.
I have forked the forum code and am planning to do some coding of my own (if I can get a test server up) with a view to trying to progress this a bit.
No doubt anything is possible, and I once converted my own forum to use phpBB, but then I found its limitations and abandoned the idea.