That's exactly it, Compact VST to fit a width restrictions. The Quad EQ has a fly out, so less common features can be changed from there, and you get use of the bigger eq display
Some come in PC fromat only -ReMatrix
Some come as both PC and standard VST - Breverb
So all XLN would need to do is make the GUI more compact, and add change some coding so that it's recognized as a ProChannel. It's already compact.