DMX-In remote planed?

what functions are you looking for? There are several ways to do remote functions currently and more coming.

I´d like to use any kind of DMX-Faderboard as a Submaster-Remote

Is there a specific reason it has to be dmx in? Currently you can use UDP to control the console and OSC is currently under testing. I have several OSC based submaster remotes and even Arduino based hardware submaster systems.