Another thing I've noticed is that if I eat a very rice-heavy meal, my blood sugar levels may rise throughout the night. I don't think this is insulin-resistance but rather my body digesting the rice. You can't expect the body to digest all the rice in 2 hours, can you, there certainly must be parts that are protected from the stomach acid until much later in the digestion process. So that feeds into the high blood sugar levels overnight in my opinion.
I think if anything, CGMs have opened up the idea of what diabetes really is and how different bodies handle blood sugar. I think I'm borderline T2D, not full-on T2D despite what my doctor says, and I've started wondering if my blood sugar has always been high, but normal for me. On average it's about 120 mg/dL, but I do see my body react properly to new sources of blood sugar and drive it back to "normal" levels, so the idea that I have insulin resistance doesn't make sense to me.