Two years and still using break-in oil.

Been kicking this around awhile and I am still not sure what do.
I put very limited hours on my 3520. Ten, maybe fifteen hours per year.
It’s got just over 30 hours so far and going into its 3rd year of what ever
warranty is still available. I have changed the engine oil & filter every year
using JD break-in oil as recommended. At what point should I avoid break-in oil?
At 100 hours as recommended? I would be using break-in oil for over three years!
Cold / dry starting is my concern and I believe a synthetic oil would be the best
thing I could do, and as soon as possible.
Any thoughts on this subject!