Brave currently only shows 60 HZ when running on a 120 HZ screen. I came to realize this as everything felt sluggish and then went to the chrome browser for comparison. Chrome was much smoother.
My test on https://www.testufo.com/ confirmed this. While chromes runs with 120 HZ, Brave was only using 60 HZ.
I love Brave, so please add the compatibility with 120 HZ Refresh Rate.