Shortcourseworld is working on one, but IMO, performance is 95% setup and driver and like 5% car. You could test based on kit setup, but that would be basically meaningless as no one runs that. You could also spend 50 hrs setting up each car, but that would take too long and still wouldn’t mean anything except who was best at setup.
I’m assuming MX and other reviews do little to no setup changes in their tests. But I don’t ride dirt bikes, so I have no idea.