This idea may not be liked by most, but I feel it is necessary for the game. I propose the current pass system is overhauled so the rewards you can get are based on player level instead of the same rewards regardless of level.
The reason behind this is I have seen hundreds of accounts rush through arenas by paying for passes and getting uniques from a low level and then blitzing up to aviary. This only makes the horrible mess aviary is worse by adding more players to the arena. Instead, by making passes give rewards based on levels, it can force players to grind the game and build their way up, lessening the congestion on in aviary.
The revamped pass would be like raids, where achieving a certain player level unlocks the next pass “rank”, giving access to better rewards. For example, levels 1-6 give common and rare dna, 7-11 give epic, 12-16 give legendary and 17+ give unique and above. Of course, the lower tiers will give more of the dna, but I see this as a necessary step to fixing the pass problem.