Sometimes you can get the closed source Mali drivers to run on Linux, but it’s a lot of work and usually requires running an old kernel. I don’t know if you can get it to work for the Orange Pi 5 though. It’s probably not worth the effort considering the poor performance you will get running x86-64 code on ARM.
You will have to use wayland to run monitors at different refresh rates without tearing. You will also need wayland for HDR. It’s still not working perfectly yet, but there is a lot of work being put into it.