Diesel are practically low RPM engine... so gunks will build up in older engine so Italian tuneup is necessary to clean your injectors.
The CDI engines such as in the Sprinter are at super high pressure so they don't have the problem as in older classic diesel injection. CDI burns so lean that the engine is practically clean all the time.
Biodiesel is vegetable oil gone through the process where they remove glycerine for health care products... such as soap, toothpaste, and cosmetics. Not all biodiesel is all vege oil... B20 or B100... 20 means 20% vege oil. With glycerine removed... there is no gelling problem as with WVO... it is the glycerine that makes oil so thick that you need to make sure the oil is hot enough to use... and always start and shutdown with diesel fuel instead.
Oil is pretty much oil... monetary sense apply here... you don't want to burn olive oil... because they cost alot! So is peanut oil.