The seat height on my Dyna Custom is under 28" and it has mids, that haven't scraped yet, not for lack of trying. Riding a Dyna with forwards kills my lower back, but the mids are great. The best seating ergos I've had in a long time was an 09 KLR650. Felt like dirt bikes of the early 70s, that allowed for the rider to move around on the seat and pegs freely.
The biggest problem with forwards and a low cupped seat arrangement is a single seating position, with no room to stretch out or change positions, taking the weight off the butt for a while. Been there, done that, and not ready to go back... tp.