Disable scrobbling of Xbox Music 30s preview "tracks" from Music Explorer

[emmaoninternet]

To clarify, I don't have an Xbox Music (or whatever MS is calling it now) subscription, nor do I plan on getting one, so this is all occurring with the Xbox Music plugin in "Preview Only" mode. When enabled, the built-in Last.fm scrobbler is scrobbling every single 30s preview clip played from the Music Explorer as a full track, which is rather silly, for obvious reasons. I think it would make sense to just prevent scrobbling of Xbox Music [preview] tracks when it's in "Preview Only" mode by default, or at least have an option to disable it.

In the course of trying to figure out what was happening and/or some hacky workaround, I amassed some possibly helpful, possibly totally irrelevant info:

• 30 second tracks will actually reach the playtime scrobble +1 threshold at 12 seconds, or 40% of the total playtime, despite the indication that the threshold should be 50%:
  
  This applies to any 30s track, including those in my library. Didn't test much, but did verify w/ a couple longer (normal song length) tracks that the normal scrobble threshold is closer to 47%
  
  
• Although the player controls show the track length as 0:30, the actual track length is still retained/displayed everywhere else:
  
  Though it appears that the scrobbler/Last.fm must still be using the 30s clip time to determine the minimum percentage of playback required for scrobbling.
  
  
• Not that it should have, but attempting to force the last.fm plugin to use URLs in the exclude-tracks-in-the-following-folders option super didn't work:
  
  
  
• Also total failure - adding fake Radio Sations using those same source URL/paths and unticking the "scrobble tracks to Last.fm" option  :\

Aaaaand that's it - thanks!