In my opinion, the dots will be excellent for the background(Not covering the entire visible area), making it look like a universe.
Just an idea that popped into my head: Lots of stars and perhaps a legend that, orbiting stars, there are planets(Though unseen so they're up to the imagination), representing the worlds there are in FeralHeart perhaps, but some stars could lack planets leaving them open to worlds to come, and perhaps when planets collide a magic makes them merge so a new area is added to the planet of the official maps, and when someone makes a portal to link their custom maps together it causes planets to merge or a magic portal connecting two planets.