[oil pan 4]

The turbo chargers used in diesels now are water cooled. The coolant in the cavity around the bearings will boil at around 250'F. Diesel exhaust temperature at idle is usually below 400'F.

The only way the turbocharger bearings will be exposed to 700'F temperatures on a diesel is if the engine turns off while on a hill climb. Still 500'F to 700'F temperatures is nothing to a turbocharger.

A gasoline engine can run 800'F turbine inlet temperatures at idle and for may years gasoline engines didn't use water cooled turbo chargers and the turbo chargers still lasted over 100,000 miles a lot of times. So every single time time someone turned the engine off on one of these older turbocharged gasoline cars the turbocharger bearings were exposed to temperatures well beyond a diesel engines worst case scenario.

In my diesel I have an electric coolant pump so I just turn the engine off and allow the coolant pump to continue to circulate.

If your transmission cant take being rolled with the engine off, then don't do it.
My GM TH700R4 transmission can roll in neutral for many miles at high speeds with out any problem. What GM did with these transmissions is designed them so that when the engine stops most the transmission fluid runs down into the transmission pan and raises the level enough to partially cover the bearings that that turn with the drive shaft.