It's hard to landscape an island, without being really methodical about it. The grid overlay doesn't really tell you anything when you're trying to flatten some terrain and make the surrounding area even. In the pictures, for example, you can't tell just by looking that the tile to the right of me is elevation 0 while the one I'm standing on is elevation 1. So it becomes necessary to mouse over each individual tile, and it's still easy to miss.
It would be helpful if, either the grid overlay provided more information perhaps by highlighting the tiles that match the elevation of the selected tile, or if we could adjust the size of the grid and apply the elevation to every tile within it.