4 deck DVS with iPad control

So I was wondering when Denon would make a 4 channel DVS system with a iPad link to a iPad like they used to do with the old engine app(2deck only control) It was a system that worked way better than Serato remote. The features like track preview scroll are brilliant and the layout is way better than Serato or Tracktor! Or is there some contractural obligations with Serato?