So, even though i sat on mine and broke it, i learned a lot from the project. I just used the 74HC4051 8 channel multiplexer and a knockoff nano. Use as many multiplexers as you need, and use the “Control Surface” lib for arduino. I can help you with it if you want assistance. It’s really easy as cake.
The next time around, im just going to give the sliders more space in-between and such. That library really makes everything super duper easy.
If you want to know how to hook everything up i can help there too. Just keep in mind that the multiplexer chips should only be used for either digital or analog at any one time. They can be used for either, but it only works with one type at any one point.