Spit IIa is now so much more inferior to the 109

[41Sqn_Banks]

AP 2095, 2nd Edition 1943

In combat and in emergencies pilots must take risks with their aircraft, balancing one risk against another; limitations must be strictly observed only in so far as there is no sufficient reason to exceed them.

I checked the June 1941 edition. It doesn't contain any general statement that aircraft or engine limitations are allowed to be exceeded. It does however explicitly state that the over-ride for the boost control of "an engine normally rated for [...] 87 otane fuel" "may be used only if 100 octane fuel is in the tanks."