Today I had no issue taking off (Lenses High mission of Folly campaign).
Then I turned Game avionics on (and forgot I did this) and could not take off no more due to lack of speed/runway distance.
Turned Game mode off, and the Mosquito takes off mid airfield runway....
Additonally, for successful takeoff I did not set any trim, any mixture, and flaps. Just full power. Some initial brake stearing, then rudder.
Be careful to not climb to fast, as you will loose all your speed!