In case it’s useful, PXT-General adds pretty good generic MIDI support to Ableton Push:
http://www.nativekontrol.com/PXT-General.html
It works pretty good in Renoise.
Do the displays and encoders work in renoise with MCU? Or is it just the note mode?
This is a nice introduction to PXT-General:
Explains how even Reaper, with ‘sort-of’ support for Push, has a lot of problems understanding the controller.
Duplex needs to do the same thing as PXT - completely re-interpret the push, if possible.
So it needs someone willing to offer their device for experimentation B)
Let’s meet somewhere and make this thing happen!
I’m planning to do a Duplex/Renoise meetup here in Berlin in the foreseeable future.
More info? Hm, still trying to think about the best way to do it, but having Push support for Duplex really is the perfect excuse 
i doubt i’d make it over to berlin but if i can help at all from afar i’m willing!
Am really looking for a good controller for Renoise right now. I have a Push, but I don’t see any links in either of the threads for a Duplex controller.
I’m more than happy to spend the money on a fully working controller - transport, knobs, faders…basically the closest thing that lets me have completely control with zero mouse.
Not sure if there is still movement on this, but I have an Ableton Push 2. I’m happy to lend this to someone for Renoise development. PM me.