The video only explains what Hotswitches are. It’s up to you how you want to use them. I’m simply advising not to take up 3 switches on a MIDI controller when you have them already there on the H90. As far as programming CC# to parameter values, this video explains how to assign CC#s to specific parameters including Mix levels.
https://youtu.be/5y14LwN9oAk?t=2888&si=T660erC9D5YY15cA
The overlays appear on the lower portion of the screen similar to how the quick knobs reveal parameter changes when you turn those knobs. Sorry, I don’t have an example I can show you at the moment.
