Hmmmm.  That does bring one more detail to mind.  The 3rd gen improvements I'm aware of are in the area around the spark plugs to enhance heat transfer to the coolant.  This raised the threshold of film boiling temperature.   Film boiling would result in hairline cracks radiating fore and aft from the spark plug holes on the inside of the rotor housings.  This can also be a source of coolant leaks into the chamber.   Look carefully, they can be hard to see.

I've seen them (not on my engines) but it was my understanding that this was a symptom of fairly long term repetitive overheating rather than a one time event.  I could be wrong about that.

Tracy