I’ve never heard of phpbb but it looks similar to other software. I have seen many forums use vbulletin with very mixed results (plus it costs money).
One of my favorite forums looks like it uses this. I know they put a lot of work into it, but I think most of that was struggling with vbulletin before they migrated to this. https://invisionpower.com/
Looks like phpbb is a solid free alternative though.
Something else I would like to see is an added section that is for non mpcnc stuff like other cool tools, machines, ideas or even just random off topic stuff.