1. Add an easy way to redownload faulty tiles. Something like "redownload centered tile", ect. Its just no good to manually snoop around in 1000s of files of the cache directory, plus with the landsat in buildup, there are many half finished tiles that have to be purged, ect.
2. Dont use height above ground as the only metric to determine tesselation of terrain. If you go to the alps, for example, 10.000m, nearly horizontal view, it will load even parts of the terrain filling a few hundred pixels at the horizon with the full x thousand triangle glory, of course causeing aliasing und stuff, not to mention the slowdown because of polygon overkill.
A nice way to check which level to choose would be a simple test: if the biggest differential between neigbouring pixels of the highfield is smaller than one display pixel in the viewpoint projection, a lower res tile should be taken. (alternatively, and more simple, a factor could be defined in the config file, so if the projection of the mesh grid is more then 1/a pixels in the viewport, a more detailed view should be loaded (otherwise the current one is ok).