Any type of frass is awesome!! Past week 3 flower it's not needed as I understand it, at least for the chitin response. Past week 3 it would just be for the biology and NPK. Like I said, as I understand it, the plant starts releasing different exudates to attract different forms of biology in order to get the nutrients and minerals it wants to move into the next stage of flowering. Doesn't mean you can't use it past week 3, its still kickass for feeding soil, but the plant has moved on from its need for the chitin and in my mind the plant knows better than me so I don't want to attract chitin solubizing bacteria when the plant doesn't have the need for them and more than likely it is moving towards a need for phosphorus solubizers to have that energy to bulk up. So I drop the chitin and pump phosphorus & amino acids alongside products like mammoth or the like.