It actually amazes me, the fact that Boruto can use Chidori without Sharingan when if I recall, Sasuke could never do it in part one without (maybe never tried). It was emphasized a few times how effective it was with Sharingan, and in Kakashi's case impossible without. As for the amount, I would say he would also be able to do it more than Sasuke could at his age, possibly 4 due to his inherent chakra and the fact that he isn't exerting more for Sharingan.