Actually, they already do
I did the lower body portion of Kelly's new Split workout. I was one of those who thought Kelly tends to go light on legs, but no more. This was a very solid workout with a few twists. I matched her (I am back to heavier weights) and it was great. My two fave exercises were the leg press on the floor and lunging back and forth moving the weights side to side. And if you love band work like firewalkers, this is the workout for you.
My only quibble is that I don't think the band worked well for floorwork, at least for me. I had a hard time getting it situated - I was using a versaloop. I used ankle weights instead.
Surprisingly, I like lower body a smidge more than upper. Either way, I think this is one of Kelly's better workouts!