A small tip: It's a bit complicated to hide a specific icon on the map. It would be better if users could uncheck them when exploring the map instead of having to find them on the left panel. Besides, an export / import functionality for what you stored in LocalStorage would also be helpful.

And there's some extra lessons from the Elden Ring map from Chinese communities: They allow users to contribute by leaving comments with coordinates. The comments are categorized into "tips", "lore", "roast", etc and can be liked or disliked, which can be filtered by the viewers. In the end it became a very useful map for all kind of players.