alt Hacker News> I would simply say: "Always use the same port for booting and installation." Which usually simplifies the process.
That would be even worse than not being able to update macOS on the DFU port. I'm supposed to remember which of 3 ports I originally used, forever??
> Maybe on another Mac/machine. When they change the machine
No, I did not use another machine.
The entire purpose of this install on an external disk was to take screenshots from my MacBook Pro. My other machine, a Mac mini, has a non-retina display, which is not good for that purpose, not to mention that the Mac mini already has multiple boot volumes, so I wouldn't need an external disk with that machine.
> That would be even worse than not being able to update macOS on the DFU port. I'm supposed to remember which of 3 ports I originally used, forever??
I simply use the port that is closest to the MagSafe. Haven't tried much with the M1 macs though, since because my M1Pro MBP was issued by the company and had lots of restrictions on it.