Have we seen any evidence of Hemalurgy on Roshar? And, as sort of an addendum, given the end of Oathbringer, was what happened to Jezrien Hemalurgy?
There are certain cosmere philosophers that would count it. I would divide it as two separate things that are using similar fundamentals... I wouldn't call it myself, but there are people who would disagree with me in-world. Have we seen evidence? I would say no evidence that is easily-- easy to pick out.
But it's there?
Yes, there are people with Hemalurgy who have been to Roshar. I'm pretty sure they've been on-screen.