To avoid having to update all workflows when a newer macOS version is published, I moved the macOS installer out of the workflow image and hosted it separately on the same webserver.
The workflow starts and macOS is installed, but unfortunately it does not skip setup assistant as set in the workflow options.
Is there a way to skip this or is it a limitation of the external installer image? Worked fine with the installer in the same dmg file.
EDIT: I also noticed, that predefined users will not be created with the external image and profiles are not installed, I guess same applies to scripts (none in our workflows).