What about the idea of adding a Tag to an instance?
Some worlds have a variety of uses, and may have different uses when it comes to party.
For example, if you need to gather avatars with elements such as furry or kemono, I would like to have a tag that informs people of the current properties of these instances, and a dedicated instance search to make it easier to find them.
Differences such as nsfw instances, sfw instances, and so on, or even more subtle differences, can be categorized by tag so that people can easily engage with their favorite tag instances.