BBpress

Not having used BBPress, I cannot say.

*If* BBPress uses custom post types as topics, which seems logical enough, then I think it might be possible using https://plainviewplugins.com/threewp-broadcast-premium-pack/user-blog-settings-broadcast-plugin/ to force broadcasting of posts with the bbpress custom post type.

If you e-mail me a reminder I can check out bbpress when I’m back from my vacation next week.

Yes, BBPress uses custom post types as topics.

That would be great, I will email you reminder.

I’ve built some support to broadcast forums and topics: the parent forum / topic will be set if the parent forum/topic is broadcasted to the child blog.

What else is needed to make bbpress users happy?