It’d be cool to have the Knights of Ren speak during the reforging scene (at least it would divert our attention from the strange chimpanzee-like alchemist). What could they say, though? A chanting of some kind? Exposition regarding Kylo’s choice?
I tried to come up with stuff here, but the only things that seemed to make sense and not just be filler were attempts at negging Kylo. “Try not to smash it this time”, stuff like that. It felt like it just interrupted the scene. I couldn’t make anything fit naturally.