Unfortunately there is no way to tell.
How much wear the injection pump has adds in. The drivers work harder with a worn pump. using lube to make up for ulsd means less friction and less work for pmd drivers. How clean you alternator is putting out, clean grounds everywhere. You environment-
The answer really is have a spare. Think of it like a spare tire. Hopefully you never need it, but when you need it it is there.
Mount the spare ona heatsink. Get a dummy plug with silicone in it. Then when dry, plug it in to keep connectors clean until needed. Then when it is giving fits and you need to test if pmd is problem, or it dies on you on the freeway in some crappy weather- just move the wire over, start and drive. 15 seconds and you are on the road.
Then when you get home and can spend some time in comfort and safety, remove the bad one and send back in for the lifetime warranty. If you have an old
One with no warranty, keep that as spare, and drive on the warranty one. Then you truck isn’t down waiting for shipping.