What if we had a game mode only through customs so 5V5 for say Lans or challenges and you could select to do AURF in it if you wanted. This way players that get bored of norms can play against each other. I'm not talking about the 5V5 when you vs randoms around your country i'm talking about playing AURF with people in your friends list. and just leave it there forever. 
I think you mean ARURF (All Random Ultra Rapid Fire)
And I don't think this is a good idea, .. sorry.
URF / ARURF gets very old, very fast.
The fact that Riot keeps it unavailable for long periods of time allows the community to miss it, as it sounds like you do.
When they bring it back for a short amount of time, people rush to play it.
If it was always available, .. I think you would eventually have trouble finding people that actually want to play it.
