[andrew_s1]

There’s wp-answers https://wordpress.org/extend/plugins/wp-answers/ too, for rating comments on wordpress posts. It’s a rough plugin that lurches into Spanish now and again, and doesn’t work on buddypress forums. However, it might offer a few more clues on how to get there.

The other thing to do would be to look for a buddypress plugin https://buddypress.org/extend/plugins/ for forums that added some metadata to forum posts.

Please do report back if you make any progress – I’ll be interested to hear how it goes.

And if I make progress with my mailman <-> forum plugin, I’ll let you know how I went about adding metadata to, and manipulating, forum posts