I actually have better simulated differential braking (better than stock) by changing a few lines in my User folder @ C:\Program Files\Ubisoft\IL-2 Sturmovik 1946\Users\wells. When you use rudder pedals and set your brake axis it will become either an X or a Y depending on which toe brake you press (L or R).. what ever it becomes.. just add the other line (If X add Y, if Y add X) and then make it a read only file and it wont change. I lie your idea better though...
[HotKey move]
AXE_RX JoystickDevice2=trimaileron
AXE_RX JoystickDevice1=trimrudder
AXE_RZ JoystickDevice2=rudder
AXE_U JoystickDevice1=-power
AXE_U JoystickDevice0=-pitch
AXE_V JoystickDevice1=-trimelevator
AXE_X JoystickDevice2=brakes
AXE_Y JoystickDevice2=brakes
AXE_X JoystickDevice0=aileron
AXE_Y JoystickDevice0=elevator