Originally Posted by artie505
Aside from not being sure what you mean by "stand-alone," I have booted my Intel Mac from an ASR clone.
To clarify, there are elements essential to the boot process that are not included in the clone so the boot process begins on the internal drive and then switches to the clone on the external drive. In the event the internal drive is somehow totally wiped out the only way to recover begins with connecting another M1 Mac to a specific Thunderbolt 4 port on the dead Mac and proceeds from there. I don't recall the exact port or process, but IIRC it essentially amounts to mounting the dead mac as a drive on the second Mac then reinstalling MacOS from there. If you are interested I think I can fine the exact instructions for the process.

To be truthful I don't know whether a macOS installation on an external drive is bootable without the internal drive or not and I am not about to wipe my internal drive to find out 🙅‍♂️ Frankly I doubt it, because at the present time the only boot volumes that are recognized in System Preferences > Startup Drive are on the current boot drive (I have heard rumors that may be fixed in macOS 12 or possibly13). To boot from any external volume requires booting into the Options menu and selecting the external volume from there and that includes an bootable thumb drive installer.


"All you've got to do is own up to your ignorance
honestly, and you'll find people who are eager to
fill your head with information"
--Walt Disney