First of all: congratulations! You have definitely built the best online map editor on the whole web. I am amazed!
Now my request/suggestion: it would be really cool if you guys could make it possible to choose customized Mapbox basemap styles in the map settings. For me personally it is crucial, since I use Mapbox to customize basemaps for displaying historical research purposes (e.g. by removing current country borders, motorways, city labels etc.). But I also know that a lot of other people like to customize Mapbox styles for different purposes, now that they have become the de facto industry leader among web developers.
Do you have anything planned in this regard?