As I fly with Rooks, ENY is not an issue for me, but I have suggested before:
Instead of ENY, make relative numbers affect downtimes.
Bish 70, Knit 50, Rook 30.
Bish kills Knit ack; downtime = 30 min * ( 50/70 ) = 21.4 min.
Bish kills Rook ack; downtime = 30 min * ( 30/70 ) = 12.9 min.
Rook kills Bish ack; downtime = 30 min (maximum).
This mitigates a numbers imbalance without depriving anyone of their favorite ride.
It is transparent to players, no need to check ENY to see what plane to use.
It is scales with numbers in real time, rather than having arbitrary unchanging ENY values assigned to each plane, and can have fixed maximum and minimum values (which can be adjusted with experience). Also, it is a "gameplay" fix for a "gameplay" issue; there are no "realistic" values to argue about.
It still provides a role for Strat killers to extend the basic downtime.
It can be easily made "local" by affecting the downtime according to numbers in a sector, or within a radar circle, etc. If a horde attacks a lightly defended field, downtimes for that field are minimized regardless of overall arena numbers.
I'm sure this could be "gamed", but it might not upset people the way ENY seems to.
My two cents....