A large part of the problem is the fact we operate engines and ancillary systems designed in the 1940s and the FARs have not allowed real developement to take place, Porches attempt to adapt their flat 6 with Mooney a prime example of regulatory impediments to what should have been a great marriage of airframe/engine.
Creampuff will be waiting a long time for engineers to make definative statements as nobody has done any long term research on aircraft in active sevice with multi life cylinders etc,
all that information comes from the operators themselves, each with their own ideas as written here and it's all anecdotal.
In the meantime we'll continue to baby our flats,rounds and PT6s
with lots of fuel and reduced power takeoffs (in complete contradiction to latest Flightsafety propaganda I notice) or as otherwise directed by the employer/owner at the time.
PS: Bring on the Orendas' .