I’d be happy for anything that easily supports closed-loop feedback. Step encoders, vibration sensors, temp sensor - all things that could help the machine to intelligently decide to STOP. Everything else - more channels, more powerful drivers, etc. - is great, but making the machine smarter would be infinitely more valuable. If the controller could notice that a bit has, or may be about to, break or get lodged in the work piece (bit deflection [ick], vibration, heat), or that the thing is shaking so much that a screw has probably come loose (I love LocTite now), or that chip accumulation is slowing down the spindle (increased current draw, air puffer not running)... basically all the stuff I do when I’m staring at the thing for 30 minutes to an hour (or more!) while it cuts a piece out of half inch AL... THAT would get me excited. CNC technology seems to be stuck in the 90s. (I’m looking at you, Mach3!) If you’re going to design a controller from the ground up, make it possible for us software guys to close the loop by providing places for useful sensors and lots of GPIO. Hell - with the right feedback, the software could determine feeds & speeds on its own. THAT would be super impressive and a huge time saver, and it’s not rocket surgery. I realize these are mostly software requests, but: provide the proper hardware, and the community can figure out the rest.