I've experimented with multiple CGMs and have been plagued with severe accuracy issues. I know this isn't the case for all people, but I found myself constantly recalibrating the CGM only to be given readings that were — no joke — 100% different than the "normal" meter's. I'm talking CGMs giving "30" or "300" when my trusted tester claimed "150."
I was careful w/ calibrations, tried for months, spoke w/ people at the company, etc etc...it just wasn't worth the effort for me. Maybe they're better now, haven't tried in about 3 years.
That was the final straw for me, but the effort around these CGMs is also not to be understated. Calibrations, extra items to lug around attached to your body, extra pieces that can break / not work, etc etc. Anything that helps with this is huge.
When I think of the big picture I realize that Type I Diabetes is nothing compared to the health issues many people deal with, and I consider myself _extremely_ lucky. That being said, it's a daily battle that you never, ever get a break from. Personally, the CGMs didn't make the battle (or my results) much better.
Who knows if this technology would be any better, but I can cross my fingers. I would gladly pay almost all spare money I have for a CGM guaranteed to be both accurate (keep me healthy) and reliable/simple (keep me sane).
Doing keto for a T1 diabetic is hard and it doesn't change that much. Sure, you don't use as much insulin but there's also no effective way of getting your glucose level up without going out of ketosis. There's also the ketoacidosis problem, which is even harder to avoid while being on keto and being a T1 diabetic.
It's a great diet for T2. And I would dare to say that paleo is even better, you keto guys (going by what I see on /r/keto) need to eat more vegetables.
The current solutions I am aware of are invasive (put a big needle into your gut and redo it again every few days), and do not allow for real time feedback. Useful in that you can analyze the data later, but hardly helps when you are currently experiencing an issue (which could be life threatening).
I'm just speculating, but the physical presence of the device itself has been a dealbreaker for me, and I've heard of similar issues from a couple of athletes (with diabetes).