For a forum that is as low-traffic as this (the bga-policy mailing list that it replaces didn't get much traffic) then it is essential that there is a system of notifying members of all new posts here. Not just new topics, not just replies to my own posts, but all new posts. And given that people can't be expected to keep checking the website, that notification should be pushed out to members.
The best technology for pushing notifications out is email, because it Just Works and everyone already has the necessary client software.
Of course, once you've got a mechanism for sending those notifications out, you've got half of a mailing list. Mailing lists require no extra software support unlike, it seems, getting notifications working in forums, so it seems that the least-effort "forum" is in fact a mailing list. Therefore I suggest that this forum be deleted and replaced with a mailing list. I recommend that the mailing list be called 'bga-policy', and that it be managed using the 'mailman' software that we're already using.