Four years ago, I made one up for my 2017 Sierra with seven positions. Since I only had 3 positions used on my original switch bank, I was able to add Aux1,2,3 &4. I bought a 7 bank switch set from a diesel that had some of the switch toggles and another 7 bank switch set for the others. I’m really pleased with the results even though I had to buy two sets. It looks totally factory. You could do the same for yours just adding Aux1 & Aux2, but you need the 7 switch board, switches and and housing. There are instructions for doing this on the GM forum somewhere. That’s where I got the incentive to make mine. Sorry, it looks like my photo is upside down, it’s -34 here right now so I’m not going out again to take another one.