This would be a very nice feature that would enable Just Map integration with various maps people make with data packs and/or command blocks. For example, the player might get various quests around the world and the waypoints would be a nice way to guide them around. Would be nice if it worked with target selectors, such as @p, @a, etc. Currently, the only way to do this is with actual in-game maps that players need to hold in their hands.