Would it be possible to expand the edges of the Dynamic map slightly?
Not easily, that's the main problem of it all.
First, someone would have to do the graphics work, with stitching new water textures around the maps. It's a bit tricky, and mostly just loads of work.
Second, all coordinates would have to be recalculated, because they count from the corners.
Third, all the map tiles would need to be recut. That's the easy part because most of it is done by script.
