fastmongrel
1st Sergeant
We can't add Merlins without costly changes. But with the Peregrine giving issues, was a return to the Kestrel ever considered? Add a supercharger? Rolls-Royce Kestrel - Wikipedia
The RR Peregrine was not giving issues (whatever that means) apart from the usual problems caused by a new engine. With practically zero development because of the understandable concentration on the RR Merlin the 305 Peregrines built lasted in service till late 1943. The only changes I know of were to allow 100 Octane fuel and +12lbs boost.