I'm going to keep this short and to the point.

It's never a good idea to update to a just-released major OS version unless you have to. Nobody knows how reliable Big Sur is going to be for regular users. Let someone else find out before you take the jump.

On our end, SuperDuper! will not be compatible with Big Sur on day of release.

As I indicated on twitter, the first time we were able to make a successful bootable copy of Big Sur at all was November 5th. As of this writing, that was six days ago.

Until that point, it wasn't possible.

So, it's going to be a while. Until then, if you must move to Big Sur, use Time Machine.