Eurorack Knob Idea

Tangential idea, but I've wondered if it would be possible to make synthesizers a lot cheaper by only having a couple rotary encoders. You could have hundreds of parameters on the panel, but each parameter would just be a neopixel LED and button. You could link the rotary encoder with a parameter by pressing it and the parameters' button at the same time. Certainly not as nice as a dedicated knob for each, but you'd also get an interface that is ~$40 instead of ~$600...

If you had a little silkscreened circle around each parameter's LED, and a Hall effect sensor underneath, you could even make a passive magnetic knob that you could use to adjust parameters by simply placing it on top of them and twisting. It wouldn't feel great due to the complete lack of resistance but it's a fun idea :)