I’d like to point people to a related topic I just posted: What the Different INA Internet Services are Intended For .
It might explain the reasoning behind the Facebook moderators trying to get discussions of impellers moved over here to Discourse. The short answer is that the INA services are each intended for different purposes. Discourse turns out to be the place designated for technical discussions. Facebook is where we encourage people to have general social interactions with friends.
I stuck more details, pointers to each of the different services, and an explanation of the reasoning behind all this in the What the Different INA Internet Services are Intended For topic.
-- Bob