Hi Chris,
I have just been playing about with XCSoar (for the first time) after loading and setting it up on my Nexus last night, so haven't yet got my head fully to grips with the various settings and options. I note your comments re lack of a vertical separation filter.
Paul,
The aircraft displayed on the 'Nav screen' show what seems to be 'vario' climb/descent rate, which I initially mistook for relative altitude and found quite confusing. If you bring up the 'radar screen' as the main screen, this shows 'Relative Altitude' at the bottom right corner for whichever aircraft is selected, though presumably this is the way it has always worked and you were asking for the option to change what is displayed on the 'Main Screen', am I right?
Regards
Peter