Yeah, excellent post about communications with Bombich software. Also, this one:

"Can CCC copy the macOS 11 System volume?
CCC will be able to use Apple's APFS replication utility ("ASR") to copy the System volume (we field-tested that functionality for the flawed 10.15.5 update). As of the latest Big Sur release, however, Apple's APFS replication utility is not working correctly with the Signed System Volume. As a result, ASR-created copies of the System volume are not bootable. Apple is aware of this issue and is currently working to resolve it."

Dave Nanian at Shirt Pocket Software says the same thing here:

https://www.shirt-pocket.com/blog/

Another thing to consider, and this is true for all third party developers, is that quite possibly two versions of such software could be required: one for Big Sur compatibility on Intel-based Macs, and one for Big Sur compatibility on the new Silicon Macs.