Why would you want to cut the bit with Kylo’s mask?
Mostly because I thought it made sense thematically for him to lose the mask when he kills his father. (And it’s never shown being recovered from the catwalk.)
I was willing to let that go when I found out he’d have the mask again for TLJ, but then it turned out he only had it…so that he could get rid of it in his first scene.
I understand the thematic purpose behind this, but think the same message is gotten across with Snoke’s dialogue, and I think getting rid of the mask in TLJ altogether won’t be all that much work, and the important dialogue can be preserved.