If we run on BoB there aren't any airspawns.
This is where I am leaning now.
Removing drop tank restrictions, keeping 2.0 fuel burn. Enabling allied planes right on their coast. Luftwaffe one sector in from their coast. At least one target town to be 3 sectors inland.
Keeping an alt cap but raising it to 20K.
Leaving town down percentage to 50% and enabling only 250lb bomb load, I figure it will take 3 formations to white flag a town in one pass. Auto calibration.
Not concerned with Luftwaffe air to air rockets so they can be enabled, I just don't want it to turn into an allied jabot fest, so disable ords for allied fighters.
Possibilities:
As Babalonian suggested, set some wind layers between 16 and 20k to hamper bombing accuracy a little and encourage lower level flight.