I just installed the Beta 3 release of macOS Big Sur. Check this out. The Beta download file was a whopping 12.88 GB! Prior Beta updates have been around 4 GB. I think that is because of all the Universal Binaries in the update for Intel and Apple Silicone. The update seems to run fine, it is very snappy. There are less tweaky little bugs as well. My main workflow Apps all seem to work properly.