I actually did, but admittedly it was maybe 4 years ago. Brave vs Firefox. Brave gave the fingerprinter a lot of information about my hardware including the exact model of my GPU, while Firefox did not.
I think I wrote some report at one time about this issue, so it was a bit more than just surface level testing. Chromium was always a disapointment whenever I attempted a comparison.
I think a more fair comparison would be today's Brave vs some hardened Firefox such as Librewolf, Mullvad Browser or even Tor Browser. Because the issue is not how vanilla Chromium or Firefox perform, but how well they can be hardened in practice.
Worth noting is that Brave does better when it comes to compatibility, because it leaves WebGL and other APIs enabled, while something like Tor Browser will disable those for privacy reasons. It hints at different priorities between these projects.