Yes. Just hit the minus indicator. Make sure you go up to 8th. Or you’ll be running 75 on the highway in 6th wondering what’s going on.... I’ve never done that or anything. It limits how far up the transmission will shift, and sort of changes the shifts points and strategy depending on how far down you go with it. Also, when you press it the first time, it shows the gear you are in by default, if it’s not 8, just hit the plus button and go up to 8. Or whatever limit you want
Side note, you can use that button to downshift manually with a load or in traffic or steep grades. I used to do it all the time when I lived in the NE.