Depending on the network connection and amount of skipped Setup Assistant steps, the successful Jamf agent installation via InstallEnterpriseApplication command and thus the Enrollment Complete trigger very often happens before the Setup Assistant is completed, at which point the current user is still the _mbsetupuser one.
This is not really an issue for things not relying on user environment to exist, like majority (but not all) software installations, but is typically a very serious issue for everything else „current–user–related”.
A very common practice is to orchestrate the entire enrollment process via script on Enrollment Complete, which waits for the actual user to login (e.g. for the Finder to appear on the process list) before triggering next steps through Custom Triggers.
With that being said, I can't really see a reason why this would impact your MUT usage in any way. I don't think there's much to worry about apart from what I've described above — and you're saying all apps and stuff installs just fine 👍
@bartlomiejsojka Thank you for that explanation.