However, since the commercial (FAR 61.129) requires a 300 nm solo cross country. I've made several of them, but they were all logged as PIC, not solo.

If you were the sole occupant, then it was solo, for the purposes of the
commercial rating. You were also PIC.

You will need to find enough time in which you were sole occupant (I
believe it has to be after the private), and notate that in the logbook
entries.

Jose

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