Grayscale map

Hi,
first I wanted to thank you for this great plugin. I would have paid for it!
Great work!
I was wondering if it’s possible to use a greyscale map like this one.
https://snazzymaps.com/style/15/subtle-grayscale
I tried to add the JSON for this map but It did nothing to the coloring of the map.

Oh and a CSV upload for mass creation of locations would be an awesome feature It’s such a tedious task to create 400 locations by hand. 🙂

https://wordpress.org/plugins/wp-store-locator/