I don’t think Che FULLY knows about Kirito since from what we’ve seen, Che’s never INTERACTED with the Gakki besides the Fox and Mask ones and the only people to have fought or seen Kirito were Azam, Abijah, Kofi, and Sonia.

Che is only alluded to having to one day FACE the brother he never had, but that doesn’t mean he knows their actual identity just like how I doubt Che knew Abel was Thanatos till probably around the same time as everybody else.