I will tell you how my advanced instructor teaches people to tune and engine. When your the student it will make you mad and crazy but you learn. The engine isn't running correctly, he tells you to twist a needle? What needle? Doesn't mater, you only have two. You twist one and it made it worse. Then twist it the other way. That made it better but not right? Then twist the other needle. What way? It doesn't mater. You twist the other needle. It's worse again. Then twist it the other way. After going back and forth like this you will finally figure it out. Your face will be red and your temper will be way up but you learned something. Then he would take you by the hand and start going over the fine points.
He was the engine builder/tuner for a big race team and a YS rep for a long time on the west coast so he knew his stuff. Just had an odd {pissyouoff} way of teaching but once you figured out what the needles do he was great. I don't teach that way but I understand what he was doing.
Sounds like you are very close to the sweet spot. Just very little twists needed. High end first then the low end.