One of the benefits of reusable map data from Commons is that it can be translated, using the JsonConfig mechanism. For example, compare the map marker in https://commons.wikimedia.org/wiki/Data:Sandbox/Adamw/Test.map?uselang=es with https://commons.wikimedia.org/wiki/Data:Sandbox/Adamw/Test.map?uselang=en . However, this feature is incompletely supported and the Kartographer SimpleStyleParser generates API calls which omit the desired map language, causing it to default to English (see example).

The uselang API parameter will trigger translation, and perhaps there's an even better way to do this?