is there any way to use multiple sprite urls with mapbox gl js in combination with maputnik? Right now we are using just our own dataset but will add more external sources in the future. Problem right here is, we can't add all the possible sprites to our own file. Non-existing sprites are just cycles. Users should be given the possibility to load additional sprite files via url to the project, so they can see the full potential of the data.
Thanks in advance.
You can't. See https://github.com/mapbox/mapbox-gl-js/issues/4086 and https://github.com/mapbox/mapbox-gl-js/issues/358
If you have some other way for users to specify images, you can call map.addImage() to add each one separately at map load time.