I'm personally using Tiled for this, which works really nicely. On a more serious note, one (and I guess the only) solution to using more tiles than fit in those few tilesets you can use per map is to do the mapping in an external program, export the map as an image and use that in RPGM. *Quickly shoves the 3072x4560 dungeon tileset into a closet* Click to expand.Right, that would be ridiculous, who would ever want that?
