DERG
An items not noted, as of yet, in your thread relative to oil temperature:
It is called "soak back". Soak back occurs when the engine is shut down and the oil coating the walls of the sump or in the tubing is heated above normal operational conditions verses if the engine was running and oil was flowing. It happens to sumps, tubing and bearing locations in very close proximity to hot components such as the frame between the HPT rotor and the IPT rotor. "Soak back" is a factor in the design of sumps and the location of the oil lines, but it is still probably the leading cause of the formation and build up of coke.
Turbine D