My huge fit breakthrough happened the spring of my second season of racing. I'd been riding a light bike with sew-ups and never considered fit. (Long before the internet and before "fit" was used as a verb applied to bicycles. The nmechanic at the bike shop I was working in encouraged me to buy the last year's bike in the basement, a Fuji Professional, at the employee discount. I did. But my good seat on, slid back because this was a 74 seat tube angle frame. Put the stem and all other adjustments in "normal" settings. Did my 45 mile training loop easy the next morning because this was a mid season change to a crank 5 mm longer. That easy ride matched my best time ever. Next time, 2 minutes came off. The times kept falling and I rode races at speeds I never believed possible for this body.
My experience may be extreme, but it also shows just how big a factor fit can be. I was riding the same seat wheels and tires. Same gears. The racing bike was maybe 2 pounds lighter, not enough to make any real difference on a course with just small hills.
It sounds like you are progressing to a better fit and that it is paying off. Keep considering foot retention. When I started pulling my toestraps tight it was like I fitted a turbocharger to the bike. (This was long before I even dreamed of racing but it was fun! That and the move to sewups were the changes that rivaled bike fit for performance. In those days clinchers were dogs. Clinchers were grandma's straight 6 sedan to Joe's 427 V-8 (sewups) in automobile terms of the era.)
Berner (post above) has some good advice re: keeping track of changes. I mark with pieces of tape the last setting. When I set up a new bike, I go for rides with no tape on the handlebars beyond enough electrical tape to keep the cables in place. I bring the wrenches for the stem and brake levers. Bars don't get taped until I like what I have. That first tape job is with old fashioned cloth tape because I can unwind it, move the levers and retape, many times if I need to. I put a yardstich under the handlebar dropout flat and mark on the seatstay where it hits. Now, on the road I can change handlebar rotation and sight down the flat to see how much I changed it. I also dial in handlebar rotation for riding in the drops, not sweating too much about what this is doing to the brake lever position. After the drops are dialed in, then I fine tune the lever location. (The reason for the cloth tape.)
Keep riding and tweaking! Report back.
Ben