Welcome to the forum.
As you probably know, native americans are very prone to diabetes due to following modern diets. At least that's how the story goes. All you said is correct IMO, but I think you should also set out to discover what that best diet for you looks like. I, a caucasion of European decent, have absolutely no idea where to find those answers.
The new standard for A1C's for diabetics is < 6.5. If you were to creep above that, just about every doctor would put you on meds. I have no issue with you staying off for now, especially with your action plan. Awesome job by the way
You should keep getting those 3 month A1C's and you should test your own sugars. You don't need to go hog wild. One or two fasting tests and one or two 2 hour post prandial tests a week should be fine. You are watching for long term trends. You are not micro-managing like us insulin dependants have to.