I also just had a bike fit. Third one in 40+ years of riding. This was a perfect opportunity because I got a replacement Kestrel frame on warranty. Interesting results. He moved my cleats outward to position the pedals directly in the center of the ball of my foot. he shortened the cockpit by about 1cm, raised the bars, changed the bar width from 44 to 40cm. I immediately noticed that I was engaging the Rectus Femorus and Vastus Intermedius Quadricep muscles far more than I ever had before. My legs were sore after a short 50 miler, but my neck, traps and Rhomboids felt great. I think I relied on the Vastus Medius more most of the work. It is taking a while, but I am starting to notice a lot more power and lower heart rate while climbing and the bike just feels very comfortable. Don't know what the wattage increase is, but, since you have access to one, it might be fun to retest after several months. I'll bet you will be generating >18 watts.
Well done.