Good job, sounds like you've got it down. You're right on about plug reading being deceptive. There are too many additives and even seasonal variables in gasoline today, add to that, most of us have a favorite oil for our two strokes, and most are really good. That said, unless you are wildly out of stoich, the plug won't tell you much. Probably one of the best investments you could make if you don't have one already, is an infared temp gun. One you have one you will find dozens of uses to make like easier. Get one with a laser. When you were too rich, the temp of the head pipe AT the jug was probably under 400 deg F. That, with the throttle at, or near WOT. Now that you are near stoic, you'll probably see over 450 deg F, over 550 deg it'll run strong, but may shorten the life. These temps are approximate too. Exhaust pipe materials and thickness will change readings too, but with some practice, it's a time saver on tuning, plus you'll learn to diagnose tons of other issues around the house and garage both over time. Have fun, and beautiful bike too!