Am I sure? No, but I have noticed that the fetch_session_complete hook is not called every time the use browses the forums or refreshes the page. Only after a specific time, so I figured it would have to do with the session time.
Got an example for both of them btw? Still a newbie at this

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Like I said.. if you have any better replacements for this, I'm happy to hear it.
if I would to include it into a hook like global_setup_complete, it would only check plugin every time the user refreshes the browser or browses through the forums. I prefer to avoid such constant checks, but rather do it in a timely matter. Unless of course a new hook can be created that only executes on the user once per hour, and only triggers once for the user when he browses the forums, and again after the hour expired and visits the forums again but doesn't check his profile after that hour expired, it has to be when he's active on the forums instead.