If buff flies +30k, it is kind of hard to use any complex tactics

Most of all, you don't have enough fuel to do that!
I think that B-26 is also too fast to try anything on it when flying too high.
Giving up with fuel modifier and making distances twice longer might help.. (map too short for any correct attacks when +30k)
But well.. we can just wait for HTC to model engines correctly, no more 24 hour 100% throttle driving for buffies..