FUDGE!!! I'm the same measurements as you!! I hope I don't have this problem! I have risers that go up 2 inches and back 1 inch. I also have highway pegs mounted on my Canyon cages. So hopefully that will change my legs enough to not cause this issue. Did you talk with him about the seat at all? Did he have a remedy or maybe change it for you? Son of a biscuit!!
You might do better with the low version of the seat if you could switch your order to that. I never bothered contacting Loren for modification to the seat because I ride all year and I don't want to have to ship it back and forth waiting for something that may or may not be better. The area between the rider and passenger portion takes up quite a bit of real estate and my butt was hitting on that as well. It is a great seat but just didn't work for me. I sat on someone else's Corbin and it was pretty comfy so I just went with that. I guess our butts are all a little different.
I was just thinking too, don't go by the fact that we have the same inseam. If your femur is shorter with a longer tib/fib, it would probably change the angle of your leg to not rub like mine. We're all a little different.