Presently, joining a full instance loads you into a new empty instance of that world.

Every moment spent in loading screens/menus is negative user experience. Waiting in lines can be fun when there are people around to share the experience with.

Please consider changing this mechanic so that instead of joining a new instance, you're added to a joint queueing instance, with some form of backend to be able to add/invite users to a near-full instance when able.