There are a few problems with Death Dragon's map when applied to DF:
- The tiles display sub tile details which are not available in any realistic fashion using the current DF map layout (i.e. access to mid level tile data). Of course, you could have a number of pre generated tiles with boundaries that do not have any actual relation to where the boundaries are within the tile, but I definitely wouldn't like misleading fake details (which would immediately be exposed as false when you look at the local map pre embark and see that it doesn't match what's on the corresponding region map tile).
- You'd need a huge number of tiles to cover all combinations of information you (or at least I) would like to see displayed, which probably requires either a large number of layers of tiles each adding its own bit, or computer generated tiles that piece the information together (which basically would be a pixel based display packaged in a tile format). You would have to generate the tiles only once with the current DF model, or at trigger points with future versions (magically produced landscape changes, and possibly gradual sphere influence waxing and waning).
- Note that with a 16*16 tile size, each mid level tile would correspond to a single region map tile pixel (ignoring that you currently can't get that information in a timely manner, so it would have to be supported by the map rewrite if you wanted to use it). If you wanted to display region boundaries correctly you'd be reduced to pixel color or a pattern to fill the region with to distinguish between different biomes (although you could use the same pattern with different color to indicate different variations of the same broad biome type, but displaying evilness as well makes even that a bit tricky). The end result would probably look more like a current day political map, where different countries (regions in DF) have different colors, than maps with little forests in green, deserts in yellow, etc. (which would be complicated by evilness, savagery, and tropicality).
While the mid level tiles haven't been brought up yet, they suffer from the same issue that the region one do, namely the unavailability of the underlying detail, which, with the current DF data layout, doesn't exist at all pre embark (and that detail is 48*48 in game tiles per local map tile, should the map rewrite generate the surface level in game tile general information together with the mid level tile one). This assumes the map rewrite retains the current 3 level system with the same ratios as they have in the current version, of course.