Install the macOS Mojave Public Beta to an external USB drive
First off, yes I understand all the caveats about beta software ... this is on my iMac, which has been my "Apple Public Beta" machine for years now (currently running 10.13.6 beta 4).
I've got an external USB drive formatted APFS that I install the OS on. I use the internal HD for my Movies, Music, and Pictures folders only.
Is there any other solution sort of a Thunderbolt dock, which I don't have?
Old UNIX Guy