I'm not optimistic, but I'd like to see if this is possible as well, an NS7III with 5 screens would be evil.

Not quite the same, but I've thought of adding some Numark NDX500s for decks 3/4, they register as Serato accessories and at least show BPM. Could help to keep everything "on the table" at least.

Posted the same question in the Numark support forum and no one asked...

Sorry, I tried to say no one replied.

Hey man, I just quickly tried this for you. It's possible to have 2 dashboards connected but I could only get them to show the alternate views, I couldn't get them to display all 4 decks. Toggling between decks just changes the view for both dashboards.

Looks like this: imgur.com

Thanks...

That actually makes a lot of sense. The toggle never could adjust the displayed deck, and gets the signal to change from the main controller.

also: since the deck indicator is a primary visual as to which deck is active, without adjusting the interface there would be mayhem. I already grab the wrong deck occasionally, complicating the heads up would be dicey.

Making a full-time heads up for 4-decks sounds like a perfect excuse to make a NS7mk4. Crazy idea, tuck a play button and pitch fader for the inactive deck on the side of the controller.

Why would you want the 4 decks on 2 Low Res poor quality small screens when you can buy a IPS High Res monitor for probably a cheaper price.

It is not poor quality, it’s enough quality for me, and I can pay that money (or buy it for less than you think) without problem. The way I have my setup installed at home makes more confortable to put those little screens behind my decks than using screen computer. I have some controllers and FX units behind the decks on stands, and those screens fit perfect in the space between decks and all the other stuff.

I have found that the Dashboard work in the same way than Serato Remote, the info that the Dashboards and Remote show is the info from the decks that have the focus (the blue rectangle surrounding the decks), so if you change the focus pressing the "~" key ("<" key in my Spanish keyboard) for changing the focus, the info displayed on the Dashboard AND in the Serato Remote app is the same, you can check that if you use Remote and Dashboard at the same time, even if you use two Remote apps at the same time (and iPad and an iPhone is the devices I'm using right now) both devices running Remote also show the same info from the same decks.
So, the problem is not the Dashboard, the problem is that Serato can only send deck info to external apps or devices for two decks at time. If we ever see a new product or an updated app that shows info for four decks, that will be because Serato changes the way the software can share the info.