Just for the record, my question was mostly intended as a reminder for myself to open an issue on the StreetComplete repo asking how to handle this. I got lazy about leaving descriptive messages because nobody was looking at (or at least interacting with them). I'll be more descriptive now going forward :)

For the record, the outcome of this one was "leave a note so someone can tag it as a gazebo using iD (preferably you, when you're back at a computer)." https://github.com/streetcomplete/StreetComplete/issues/3109