I haven't said anything about Big Sur yet, and since the public beta has been out for a while, and I'm getting more questions about it, it's time.
At present, it's not possible to make bootable copies of Big Sur, even with asr, Apple's own built-in replication utility. As such, we haven't released a Beta, or even an internal Alpha, because it wouldn't meet our own requirements.
So, for the moment, we're holding back, hoping that Apple will fix the issues and allow 3rd party (or even 1st party, given asr) bootable backups. While asr was failing completely in previous builds, in the most recent one it isn't able to back up because the system volume isn't properly 'sealed' (which is ominous, since why wouldn't a standard install be sealed, and if it's not, why wouldn't you be able to back it up anyway).
So, while progress is being made, we're kind of stuck waiting for the king.
In the meantime, my advice for macOS Betas remains as valid as ever: do not install a macOS Beta unless you have a critical business need to do so. These Betas, even when public, are not for general use, and certainly not for anyone who wants a reliable system for day-to-day work.
If you must install it, use Time Machine for backups for now (and, given my advice in Practices Make Perfect (Backups), on a continuing basis in addition to other methods), since it's at a relatively equivalent Beta quality level to the OS itself and is explicitly tested and supported by Apple.
I'll be back when we have additional news to share. For those in the US, enjoy Labor Day weekend!
