It looks like there is a third party website that can do this: https://modlookup.3v.fi/

It seems nuts that this isn't possible for yourself (though it makes sense that you wouldn't want to make it so, e.g. abusive users can see every channel you're a mod on to harass you there). At the least, I want to be able to check where I'm a mod, and demod myself from places I don't want to be listed as a mod anymore.

Why be a moderator if you don't know the channels where you moderate?

you can already do this but an editor

well? is this a thing yet?

Just seems too insignificant for Twitch to bother with. I mean it might be neat to have some kind of indicator in chat to remind you you're a mod, but that's it.

It would be beneficial as someone who mods 50+ channels and follows 1000, it's nice to have a list of the channels that I should view as a priority to watch or at least check on. Sometimes people will make me a mod & not mention it, so when I do go in there I'm surprised to see the sword. With the list I probably would have stopped in more often. Like channels have /mods to see the moderators, it'd be nice for moderators to know where they are a mod.

Could you elaborate? How would this be beneficial?

This is a good idea!