I think you are still fine tracking them. My new rotors looked like that after a weekend using PFC08s.
Run your fingers over them, if you can get a nail in there, might be cause for concern. Also, once they start getting close to the edge it is more of an issue.
Here are some BMWP rotors that saw about two seasons. The advice I got on those was that they still probably had a couple events left. I was able to feel those cracks quite easily, and didn't really feel comfortable, so I swapped them anyway.: