I was unable to find any documentation on this as well, but I have requested it here:
As you have figured out, System Users are users required either by add-ons or used by Atlassian Staff to troubleshoot your instance. They do not take up a license seat.
I hope this helps! Let us know if you have any additional questions.
...word of mouth, so by 2016, we were working with several other entities on campus to implement Jira Service Desk . The Atlassian motto of “for every team” has really come true for us in this case. We...
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