I run a salary cap league and once a week salaries of newly released free agents have to be reset to the minimum per our rules but MFL has no setting for that so I do it manually.

Also, we have a KR and each time a team adds a new KR, they have to message me and ask that I give that player (typically a WR, RB, or CB) KR eligibility.

I also write league articles and make other update announcements that I feel like are more "official" when done under the commissioner username.

Obviously not all leagues have these setting but then I also don't approve trades, those just happen, so every league is different. Those are the only ones right off the top of my head as well as the other one mentioned that when I log into the site it takes me straight to commishing. I'm sure there are a few others I'm not thinking of.

It honestly hadn't occurred to me that some league mates might get a little freaked out by seeing the commish logged in but we're mostly a league of people who know each other in person and have been in other leagues together.