Yep just wrapped up installing Big Sur using clover (5126) on a Haswell system using 15.1 sys definition. Installed on a external drive. Took a while like 3 reboots, but no real issues. I only poked around adjusted some settings, but for the most part seems like everything works, sound, network, dual monitors etc.
As for the OS itself... very ipaddy like, lots of puffy wasted space for the same stuff which was more clearly defined before, wellllll... I guess that is a topic for a different discussion.