Hi Bob,
No bypass in mine and no hear resistant paint. A friend of mine you also has a 2M reported that his fuselage was getting very hot after turbine shut down. He added heat shield paint and that helped a little but he was still worried, so he added the bottom only part of the bypass ( To direct the warm air away from the fuselage more than anything) and that worked a treat.
What surprises me is that he is running exactly the same turbine set up as me, and I dont seem to have any issue with my model. I guess it might be to do with turbine positioning in relation to the tail pipe. I recently had an issue we re-circulation on my ME262 heating the fuselage up and actually causing it to implode as my turbine was too far forward.
Regards Al