I am originating a new usage of the ✅. I hope it catches on, because in a sense it's mostly used this way now.

As portability is currently quite limited, the checkmark now indicates that I am actively using that instance, and that my other nonchecked instance identities are hibernating.

It's not fancy, but for now, if it becomes the norm, its absence can then serve as a signal that you've moved. Link to where in your bio, and then followers know where to go look for you. Would be neat to just scan down my Follows list and see who I'm missing by the lack of checkmarks.

In the future I hope we can make lists follow users around (This will take a lot of work to architect right within the federation model, but the federation model is worth the work.)

Additionally, I have chosen to use the Mute symbol to represent inactive instances. (see @five ) Feedback? Does this feel intuitive?
@five @five Apart from having account status on database (and thus being able to search by status) this is the best solution IMO. It feels like the internet went from emoji noise-deluge in handle (messenger era) to emojis marking corporate approval (twitter) and then to emojis as social convention to cover for a new emerging platform's lack of features. I like this progression.