Why do you think we fly such vintage machines as the Chippy, Firkin L? It's becuase they have 'character', and in the case of the Chippy (unlike spamcans) they also fly properly - e.g if you move the stick a tiny tad sideways the aeroplane rolls, instantly and accurately. Move the 'steering wheel' in spamcan a similar amount - wait - and wait - and...not much happens, certainly nothing with any accuracy about it.
Putting a Lyc in a Chippy is like adding a glass and steel extension to a thatched cottage; it may make it more practical, but it's no longer what it was any more and the world is the poorer for it.
Lycs rotate the wrong way for the Chippy airframe, too. If you fit the ring mod, Gipsys use no more oil than a Lyc, and only spill it over trhe airframe during aeros (which are beyond the capability of most lyc-engined aeroplanes, so they don't suffer it. I bet Extras do!).
The RAF wired carb heat to 'hot' because unlike a Lyc or Conti carb heat on a Gipsy gives warm air, not hot air. Consequently the power loss with heat selected is small. The RAF operate out of long hard-surface airfields so the take off performance loss was not important. We operate ours out of a short grass field so we take off in 'cold' and then switch to 'warm' for the rest of the flight.
SSD