I use the Libre periodically now. About 12 months into my “journey” it became available in the U.S. I have a very obliging doctor who well knew how focused I was on making the necessary changes to improve my health. I had already achieved a non-diabetic A1c at that point, so it was no doubt a stretch for her to prescribe, but I’m thankful she did.
At first, I used it 24x7. I found it fascinating and so helpful. But, for me, it showed the further HFLC I moved, the more my fasting (and overnight) BG hung high after a really fatty meal. So, I adjusted to more moderate carb (150g ish per day), which admittedly was my preference anyway, and was very pleased with the results. These days, I use a sensor every 2 months or so (6 weeks off, 2 on) to make sure I’m still on track. A1c has remained in the low 5’s, high 4’s since. I very rarely test in between sensors.
so, while I can definitely get on board with a (relatively) inexpensive CGM type device being really helpful, I’m not sure it will support HFLC with doctors anymore than a good A1c now does. I think having a CGM as easy an a smart watch would be a game changer, but mainly just for healthy eating across all macronutrient ranges for the metabolically healthy.
edited to add: to confirm, T2, no meds