I finally discovered a way to add grids to maps in such a way that the grid only shows inside rooms instead of on the entire map. I updated Free Map 1 with the new grids (a hex grid and a square grid). Next week I will release the updated map as a Pay What You Want product through my DriveThruRpg merchant page (DriveThruRPG.com – Cool Games Lab). Below is an example showing the square grid.