Here's an idea to decrease some of the imbalance in ARAM.

Lower the free CD given early.

80% CDR right out of the gate sometimes means your match-up at level 1 is just brutally crushing. Regardless of ARURF or URF. So why not remove about half of the free CDR?

Slowly either give it back over the course of the game (10% after 5/10/15/20 minutes) or just make CDR actually something you purchase. "But then urf wouldn't be as fun" is probably the biggest argument but c'mon. Who has fun sitting at the tower, trying their hardest to avoid veigar cages at level 2? (Inb4 troll response about the exhilarating gameplay of Veigar locking you two meters behind your turret.)