That may be well intended, but in reality what the fuel multiplier does is force people to fly longer ranged planes for anything except base defense and furballing.
Where are you flying? Here are the kill stats for tour 71 top 10.
Rank Type Kills Deaths K-% K/D
1 Spitfire XVI 43991 38519 10.85 1.14
2 La-7 36721 30634 9.06 1.20
3 N1K2 30032 25117 7.41 1.20
4 P-51D 25777 24621 6.36 1.05
5 Typhoon IB 22640 15014 5.58 1.51
6 Bf 110G-2 17592 22214 4.34 0.79
7 SeaFire 16085 18221 3.97 0.88
8 Hurricane IIC 15793 12328 3.89 1.28
9 F4U-1C 12379 5346 3.05 2.32
10 Fw 190D-9 12332 8245 3.04 1.50
How many of these are long range American fighters.
No one will fly on cruise in hostile airspace and be bounced from above like you want. In the MA speed is life, and if people can't fly a plane like they want they will switch to a plane that can. In real life pilots didn't have that option.
In real life pilot used cruising power to fly into hostile areas and only used mil and WEP power when in combat. It is not realistic to fly at Mil power all day, that IS why we have an FBM.
What are you flying that you do not get enough flight time out of?
The answer to realism is to make the FBM higher not lower, or just move the bases apart.