At least one operator in the UK used to have a similar approval on their Seneca fleet to run on condition based on enhanced inspections and the aircraft flying both day training and night freight - from memory their approval allowed up to 3500-4000 hours between major overhauls, and most of the engines made it. Very few issues between normal checks in those hours, just because the aircraft were either flying or being maintained. Perhaps a concept that might return in due time in the UK post-January 2021, as the UK CAA continue the idea of Risk Based Regulation.