A Viking sportfish was in front of us in Key West having its regular 1,000 hour check. Two mechanics were working on it over several weeks (corona virus shut-down may have affected scheduling?). I saw four turbochargers r and r for checking, at least one head, lots of other stuff I didn't pay much attention to. Dock talk was that this had to be done every 1,000 hrs. to maintain the warrantee. Required to use only MTU fluids, filters, parts. If you ever missed one service the entire boat would become unsaleable for lack of this maintenance because no one would purchase it. Cost was said to be over $10,000 per engine. I don't know if there were underlying problems included in this but it had been out fishing when we first arrived.
It did make me think about my now 25 year old 6V-92TA Detroits. Other than annual oil changes and one leaking fuel/transmission cooler failure (replaced both) I have only had one engine have a tune-up in all that time. Something to be said for the old iron!