I am wondering if anyone has bothered to create more realistic atmospheric data for the Earth where the atmosphere does not just dissipate after a certain altitude. Is the lack of atmosphere after a certain altitude a limitation to orbiter or was it designed like this on purpose to deal with time acceleration
You mean above 200 km? The cutoff is deliberate.
I heard Orbiter would have problems dealing with the small numbers representing drag forces. Besides, at that height, I hardly think the usual gas equations still apply... gas starts behaving more like single particles then a continuous matter...
Making a more complex atmospheric model is somewhat difficult, especially because it's hard to make a function to describe atmospheric density over altitude. it relies on a lot of factors, such as pressure, temperature, solar activity,...