flybubba, whilst there's a few 'Engine knowlegeable' people close by, may I borrow your thread for a moment? (Actually, it's the reverse of your question).
I'm familiar with the need to allow cool-down before shut down, an engine that I operated some years ago, if shut down early, had to be motored within 20 minutes to expel residual hot gases and reduce uneven thermal distribution. So far so good.....
For the engine that I presently operate (RR Trent), start (Auto and Manual) is not initiated until motoring has reduced the EGT to 93°C. I was recently unable to answer a trainee's question of - "Wouldn't it be less thermal shock to initiate combustion in an already hot engine, rather than for a cool engine?". I had to admit that I didn't know why, but opined that the motoring / cool-down cycle was possibly required to ensure more even thermal distribution before the 'thermal shock' of combustion.
Any opinions appreciated, with apologies to
flybubba for the thread-jack.
Regards,
Old Smokey