[edited to add descriptions to each link, since I guess I had too many for previews to populate]
Re non-civil 4e conversations here. I'm not sure I agree. I have enjoyed several nice 4e threads here. A search reveals a few:
This is a pretty good
thread tbh. Its most recent post is only 18 months old, so wouldn't be a terrible necro (unlike the 2007 one I found). "D&D 4E Let's Talk About 4E On Its Own Terms [+]"
This
one's pretty civil too, also from the same time frame. "4e Essentials as a new edition and 4e's longevity"
Seems like late spring last year was a hot time for 4e on the old World of EN. Here's another good
one, imho. "Using 4e elements for your 5e games?"
Last one - I liked this
conversation too "Crunchy Tactical RPG like 4e/pf2e but for Urban Fantasy?"
Nope I lied, this
one on the cosmology of 4e iirc was pretty civil "4E Cosmology"
All of which to say, I think civil convos about 4e happen here. None really recently though (except this
one I guess). "Games Inspired by 4e D&D (+)"
That's really on all us 4e fans though, not the board itself. Let's start some 4e discussion! I've got an idea for one, but it'll be a bit, as I guess I'm actually supposed to be working

I'm also going to come back to the Urban Fantasy one...