I know this is an unusual request in some ways.
As can be clearly seen on this modeling color chart the Mosquito FB.VI "Black Rufe" possesed "Exhaust Flame Damping Shrouds" or "Ducted Saxophone Exhausts" (whichever term you prefer) that significantly reduce performance. The only purpose to these devices was for night operation which AH doesn't currently model.
The Mosquito is already a marginal aircraft in the context of AH. If it is modeled with the exhaust damping it will be even less useful as even N1K2s will outrun it. It would be kind of ironic if the Mosquito were to be one of the slowest aircraft in AH, even at sea level.
Given the kind of combat that it will be used for (daylight) the first thing that pilots would demand is for the exhaust damping system to be replaced with exhaust ejector stubs in order to give some slim chances of survival. 14mph (and whatever acceleration and climb improvement) can make the difference between survival and death.
In an environment in which very fast aircraft are much more common than what the Mosquito FB.VI had to deal with in reality it would be a shame to reduce the usefulness of the Mosquito by modeling it as the slower of the two possibilities.
Thanks.