Re: Plugin active only in certain forum
There’s rumors of a wiki-based codex coming up after bbPress 1.0 goes gold! Hopefully that should help with documentation…
This tag plugin looks somewhat similar to what you mentioned:
https://bbpress.org/plugins/topic/list-tags/
But there are reports of bugs with it. I’m guessing the plugin only works in .8 and .9 versions – tags completely changed in version 1.0, so that may be the issue. Still, might be worth studying the code for inspiration!