If you have a solution for it, shoot. 
a) streamdetails can't be manipulated from the outside (at least they are not supposed to atm, no setter methods)
b) we can't cache shit here, because we did not parse the actual stream, so stream could be stereoscopic but we don't detect it by video settings nor filename. So we can't set the stereomode to "mono" just because we didn't find anything here
c) with current structure that users can set a custom stereoscopic mode in video settings we have to parse those anyways

In a perfect world streamdetails won't be overriden by dvdplayer on each playback, the stereoscopics mode would ONLY be stored in streamdetails and could be updated from the outside. But this is not possible atm. First thing to fix is to not overwrite streamdetails on each playback. If this is resolved we can fix the rest. I already started a thread in internal forum about 3D stuff that should go in/be fixed for Gotham. A solution for this is also in there, which would finally allow a smartplaylist filter for stereoscopics (which is a no go atm).