Not sure how nobody made this Vs Thread before, but here we go.
Sasuke is his latest version, so at the point of the Boruto Manga.
Kakashi is during the fight with Kaguya when he acquired DMS.
They can obviously use any ability that they displayed.
Keep in mind that they can't fight forever and that they have exhaustion levels, namely if Sasuke uses his rinnegan too much and that Kakashi can't keep his DMS forever because of Obito's spirit. Saying that, Kakashi can keep his DMS up for more than 5 minutes, despite his limit during Kaguya's fight.
They obviously know about each other's ability.
They fight in Kaguya's last dimension, so its open grounded.