[PeterVerney]

While my experience is not strictly relevant to the thread, I'll stick in my two pennorth.
We had Mosquito night fighters with 4 fuselage mounted 20mm. We then upgraded? to the Meteor night fighter which had 2 20mm in each wing, mounted outboard of the engines.
We got lower scores on air firing exercises with the Meteor and particularly noticed stoppages as a problem. A stoppage meant abandoning the exercise because the yaw induced made accurate aiming impossible. Whereas on the Mosquito a stoppage had no effect, except for reducing the number of rounds fired which reduced the score.