you bet - cold running is worst.
I have seen some taxis in germany - mercedes benz CDI of course, they would only be shut down when pulled into the shop - it was a literal nonstop thing, even refuelling was with engine running, drivers changed on shifts, engine still running.
the engine only shut down when about to be put on service rack - Their mileage and engine hours would make you scratch your head, The highest I recall was at 820,000 kms. The guys told me that they have seen some models with more than 1.2 million kms - and the cars were then sold - not scrapped. lol