So here is a couple measurements from a 2020 which should be the same for '17 and up?
Laying the tape flat on the tank and seat, 6 3/4" from the bottom of the ignition switch to the tip and 22" from the bottom of the ignition switch to the seam at the bottom of the seat.
I can' t send the seat to Mean City. I live in Germany...
I look again at the Mustang Touring and Corbin. Unfortunately there are no retailers to test here. I had already tested the HD Low Profile. It also puts me too far back and down.