No, the machine (if set to full security) needs a signed ticket from Apple specific to your hardware (ECID) to run. It's just like an iPhone/iPad in that regard. Disabling the internet means the update will fail.
Remember TinyUmbrella and backing up your SHSH blobs so that you could downgrade to previous OSes? It's that same API.
> No, the machine (if set to full security) needs a signed ticket from Apple specific to your hardware (ECID) to run.
Thanks. I see now that it's somewhat documented by Apple, except the plaintext aspect. So it seems that "Reduced Security" would be the workaround.
https://support.apple.com/guide/security/startup-disk-securi...
It's easy for the os to stack up the updates and the push everything once the network is back up.
See:
Question about this article: At what point exactly during the update process does this happen?
As a workaround, could one do softwareupdate --download from Terminal, turn off your internet connection, and then do softwareupdate --install?