A piece of advice that seems to be widely accepted is that after a long high-speed run, when the turbocharger is thoroughly hot, you should let the engine idle for a while before stopping it. The reason given is that this allows the extremely hot turbo bearings to cool down a bit while the lubricating oil is still flowing, so that the bearings don't get contaminated by burned-on deposits.
I can understand this, and I can also understand the advice that often comes with it, namely that normally it isn't very important because at the end of a typical journey there will be quite a few miles of relatively slow driving between leaving the motorway and arriving home.
Here's my question. If it's all true, why are we not told to let the engine idle for a while before filling up at a motorway service station? I've never known any expert to give this advice; equally, I've never seen cars waiting before the pumps in a service station with their engines running.