Sandhl - I suggest you look at PlanePlotter, it handles both pos and non pos aircraft and gives you access (i.e. ability to record) all network data not just your local data. You can also MLAT non pos to make it positional.
PlanePlotter also has a useful feature which works even when there aren't sufficient users to MLat an aircraft - it's able to tell you which locations a specific non-ADS-B aircraft is being picked up from, and where the coverage from those stations overlaps, which is usually enough to tell you roughly which part of the country it's flying over.
I'm surprised at AirNav's stated reasons for dismissing the display of non-positional aircraft on the grounds that it would require development effort and impose more load on the server.
Exactly the same arguments could be used for not developing a RadarBox MLat system, and yet we're told that's in the pipeline.
Displaying non-positional aircraft would be a step in that direction, if the system can't cope with that then it's hard to see MLat ever becoming a reality.
