As a hobbyist maker/electronics enthusiast, I would very much like to be able to control blocks on my ship though a midi device.
Currently, it is quite simple to rig up a $0.50 button soldered to a $5.00 micro controller and have it act as a USB keyboard, which could be used to trigger events from the hot bar in-game. However, I would like to have much finer control. By allowing us to have a programmable block that reads values from a midi controller, it would open up an entire world of possibilities for unique control schemes to those of us who own, or are willing to make midi controllers (which, given the DIY nature of the SE community, is probably a lot).
For example, if I can map the output of a potentiometer knob to the position of a rotor (using an Arduino or similar device), or the position of a slide potentiometer to a piston, I could very easily create my own control device that could smoothly and intuitively operate a crane in-game, adjust vectored thrust, smoothly adjust ship throttle, or any number of other applications. The possibilities are endless.
My ultimate fantasy would be to build a 6 DOF arm out of plastic IRL with a potentiometer in each joint, reporting their positions to rotors in game and allowing you to physically manipulate the arm in real life with your hands, and see those motions mimicked by a similarly proportioned arm in game. That last part might be a bit of a skylark, but the core concept is practical, and could make a the game a lot funner.