I think this is already possible with the current very flexible setup you can create you own mission for one plane and then from this mission create a template for all other planes.
You can do this like in the following example:
Mission for BF-109E-4
[MAIN]
MAP Net1Summer/load.ini
TIME 12.0
CloudType 1
CloudHeight 1000.0
player g0100
army 1
playerNum 0
[Wing]
g0100
[g0100]
Planes 1
Skill 0
Class air.BF_109E4
Fuel 50
weapons default
StartTime 0
[g0100_Way]
TAKEOFF 37365.44 33856.39 0 0 &0
NORMFLY 38058.33 39807.77 800.0 400.0 &0
NORMFLY 30658.70 39769.95 800.0 550.0 &0
NORMFLY 30611.75 22582.50 800.0 550.0 &0
NORMFLY 36633.80 22426.95 800.0 500.0 &0
LANDING 37275.10 32139.74 0 0 &0
TLGen Mission Template[MAIN]
MAP Net1Summer/load.ini
TIME $Time$
CloudType $CloudType$
CloudHeight $CloudHeight$
player $Wing$00
army $ArmyNumber$
playerNum 0
[Wing]
$Wing$00
[$Wing$00]
Planes $PlaneCount$
Skill $PilotSkil$
Class air.$PlaneClass$
Fuel $TakeoffFuel$
weapons default
StartTime 0
[$Wing$00_Way]
TAKEOFF 37365.44 33856.39 0 0 &0
NORMFLY 38058.33 39807.77 800.0 400.0 &0
NORMFLY 30658.70 39769.95 800.0 550.0 &0
NORMFLY 30611.75 22582.50 800.0 550.0 &0
NORMFLY 36633.80 22426.95 800.0 500.0 &0
LANDING 37275.10 32139.74 0 0 &0
Just look at the highlighted parts!
Hope this helps you into creating some very nice war time action TLGen template(s).
Just remember you can alter the aircraft configuration file so you can generate the mission for example for only GE planes or a specific set of US planes.
By the end of next week there will probably be a newer version of TLGen with more possibilities.