Great story! I find my GSD loves to work so that he can work some more...
"READY!" is just a cue for tune in to handler so we can do more..... "Sit" is always a fast square sit otherwise we cant move to the next behaviour.... etc
My Beardie X on the other hand doesn't move unless a food reward is coming at some point.
Assuming we know what motivates our dog just never works I find it takes months of experimenting to truly know what they love.