I know some people running their diesels on Jet A1 for years without problems, I even know one person who runs his car on the fuel drained from aircrafts and helicopters during checks and maintenance (THAT is real enviromental friendly recycling
).
Thielert had to change the high pressure common rail pump on the Centurion engines to make them work with Jet A1, due to the much lower viscosity sealing was the problem, so there was a remarkable ammount of leak fuel in the pump housing to be drained, and the maximum fuel pressure was not maintained at full throttle and low rpm. Lubrication was obviously no problem.