The "documentation", if you can call it that, was entirely contained in a popup the first time I selected "Full Clone (Beta)" as the backup method. Because I imprudently clicked "don't show this again" I can't even get back to the popup to read it again 🤬 There was more information in the popup about snapshots that I really want to take a longer look at. â“â“â“
I don't remember seeing that pop-up, but
Performing a Full Volume Clone via Apple Software Restore (Beta) is probably what you're looking for.
I'm actually one (unreleased) build ahead of you with CCC 5.1.15b1 (589
1), which enables bootable clones of your boot volume in another volume in the same container if SIP is disabled.
Talk about fast? A Full Clone clone of my ~25 GB boot volume takes ~1 minute 5 seconds whereas a Copy All Files clone takes ~3 minutes 55 seconds! (And incremental updates sound like lightning!)