I think a retake server with a max of 5 player would be dope because me and alot of buddies play retakes but hate when random people join, and i think the 5 man retake would satisfiy everyone who would play on it
Only problems with this is that most hosts rent out a minimum of 10 slots so he would be paying for 10 slots and forced to only use 5, which again makes it harder to generate enough money to keep it up and running.
If you want a server specifically for you and your buddies to play on you could always go rent one? But the idea of it only being 5 slots because you and your buddies don't like it if other people join when you are playing retakes. What happens when someone gets 1 of the 5 slots? You still have a "random" in your eyes that is outside of your group. So you still again have the "problem" that you mentioned in another post.
So yea the solution to your issue is not to have DMF put a 5 slot server up. It would be for you to set up a retake server for when you and your buddies want to play with just the 5 of you.