It doesn't leave any room. If you look at the seat rail it's actually two rails (one above the other) running around the seat with a tab in the centre to bolt it down to the rear fender in the same spot the solo seat is bolted down. The upper rail runs high enough around the seat that you don't have to touch it at all. The lower rail would run right into the pillion pad, that area is where you would have to remove the rail to have both in place.
I imagine cutting that out and removing the centre tab for the bolt would make the rail easy to grab and pull up because of it being attached only on the sides.
