I noticed that the extension includes prunecluster but I'm not sure how to use it on a wiki. Can it be turned on using a mapframe or only through js?
Topic on Help talk:Extension:Kartographer
it's automatically used by Wikivoyage. There is a Wikivoyage mode in the configuration that you then need to enable and that then looks for MediaWiki:Kartographer.js which has to contain a defined url in nearbyArticlesCfg, which returns points of interest in a very specific manner. It's a bit of a hodge podge honestly