Put tiny chips on for feet that cannot be used as a handhold. Make them small and slopey, or very tiny edges. Even small edges can be crimped on. Using chips for footholds allows the routesetter to create interesting moves and body positions, without creating additional handholds that destroy sequences. These footholds might be way out to one side of the line of handholds, or even directly underneath or above handholds.
Shorter climbers can make longer reaches if a foothold is placed high relative to the handhold.
Your route might end up like this, using larger holds for hands and handholds plus tiny chips for the feet. A taller person gets more bunched up, their center of gravity is further out from the wall than a shorter person, and especially with small holds, the tall person finds it hard to hold on. In this case, use holds that are only underclings. These underclings require your feet to be on footholds to create the opposition required to keep you on the wall. Routesetting Tip Number 5 Create cruxes.