My thinking is that HSFX dudes need to fix the Spitfire XIV mod pack rather than TD trying to fix something that they didn't work on. The regular Spitfires, even the hot rod Mark IX +25lb flies great on 4.11.1 with a little throttle manipulation. Since the radiator is fully auto and there are no controls over it you just manage your throttle a bit.
You should in most planes be able to run 90% throttle, 90% prop pitch (which is really the RPM control) with rads open and no climb almost indefinitely. Since the Spitfires have automatic rads and pitch... 85% or 90% throttle is usually my ideal range.
The only exceptions are if you are nose high in a climb. Heat rises rapidly under the new modelling as it does if you are constantly at low speed or in a stall turn situation.
My guess is that the HSFX guys wanted the XIV to run a little hot so they overdid it and now under the new modeling it doesn't just run hot, it's a BBQ. Be nice to have the XIV in the stock game mind you
