That said, it sure doesn’t seem like there’s a lot of activity here, unfortunately.
I think it’s a bit of a chicken-and-egg thing. I post here from time to time, but what tends to happen is that there will be a little flurry of activity, then it dies away, then I get out of the habit of looking – thus I’ve only just seen this thread, even though you started it a good 6 weeks ago.
There is a sub-reddit for recorder that is a lot better than the clarinet one which, as you suggest about facebook groups, mainly recycles the same 3 questions (in fact the mods recently put up a note asking people to search before posting, it’s so repetitive).
There used to be quite an active ABRSM recorder “forum” – it was actually only a thread within the larger forum framework; it was active and generally useful but ABRSM shut down the umbrella forum so it went. A bit of shameless plugging here: some of us set up an alternative as a continuation which you might like to look at. I hope it’s ok to post details of another forum on this one? It’s at TMS but it’s all music, not just recorder, and to be honest the recorder bit hasn’t recaptured the dynamic of the old thread. It’s a nice friendly place though and could use some new blood!