No, lowering the capstone isn't what we're suggesting. Using the 'stub tenon joint' as a pivot point is more like it. So all the energy of lifting and placing the capstone can be directed at the other end of the stone.
Hmmm, I like that less. All that effort creating the stub when you could be getting on with the job. You wouldn't make a stub if you were in a capstone-placing race would you?