All I can tell you is when I re-cloned the data volume of a bootable Big Sur clone it was no longer bootable and Mike Bombich has reported similar results and IIRC he did not indicate there was any difference between Intel and Apple silicone in that regard.
Just to be certain that we're on the same page, after creating a bootable (Intel Mac) Big Sur clone I ran "Copy All Files" daily, and the clone remained bootable. In fact, I discovered that the system volume remains untouched even after macOS upgrades by booting into the clone and looking at "About This Mac."
Got me beat!
As we've already discussed, though, competing with Time Machine is an awfully big challenge, particularly if he hopes to perpetuate CCC as a $40 app.
That is a question only the market can answer. As I have said before this whole episode has lead me to re-think the value much less necessity of bootable clones.
- While I continue to keep a clone around, it is more from habit and/or convenience not out of necessity. *¹
- I cannot recall ever actually using a clone for anything other than an experimental purposes
- If you read the latest CCC User Guide Mike Bombich does not recommend the use of a bootable clone for backup and seems to question their usefulness
- The M1 Mac boot process always begins on the internal drive and ASR clones are not bootable stand-alone which further limits their utility. I don't know if this is true for Intel Macs or not
*¹
My layered Backup Strategy In retrospect I am going to look at how to fold CCC into my strategy (would that be belt, suspenders, and elastic waistband?), but it is doubtful a bootable clone will be included other than as a toy or proof of concept.
I can think of three instances in which I've actually used a bootable clone:
- The underlying reason for maintaining a bootable clone, as a fallback in the event of HDD failure, but, as documented by BackBlaze's Hard Drive Failure Rates for Q1 2021 (caveats notwithstanding), SSD's, which, in the context of Apple's "never look back" mentality, are what all of us have got in our Macs now, simply don't fail often enough to demand backup.
- I've booted into clones to manipulate stuff that couldn't be done while booted into my boot volume, which, since Apple locked the system volume down in Big Sur, can no longer be done.
- I still find a bootable clone useful for "volume manipulation," which would otherwise have to be done from Recovery, simply because it takes considerably less time to boot into the former.
In short, as suggested by Mike, they're not particularly useful at today's date.
Aside from not being sure what you mean by "stand-alone," I
have booted my Intel Mac from an ASR clone.
My "layered backup strategy" at the moment is a day old bootable clone, a two day old bootable clone, a month (maximum) old bootable clone, and Recovery/snapshots. CCC's new snapshot exploration functionality will eventually become an important layer, but I'll still maintain data clones for their simplicity when they're applicable.
