Even if you get everything set up the same, two saddles interact with your body differently. Bottom line is they all compress differently and have a different natural “sit zone” as well as how they interact with the body while riding aero. I had to change my saddle 10 days before Kona due to a broken saddle rail and had to opt for a different type and I was moving the seat around slightly fore and aft and tilt until I felt I got things dialed back. This process continued until 2 day before the race. Not optimal, but I had no real choice with last moment change. I think Paulo’s approach would yield better results