I was diagnosed type 2 diabetes ~20 years ago. I did Atkins for almost 4 years. I ate a little more protein than a pure Atkins because the Doc said it was a little too high fat otherwise. I lost about 40# and it did help bring the BS down. The problem was it makes your body PH high and I started getting kidney stones because of the high PH. I have passed about 15 or more 1-2mm stones over the years even though I stopped the Keto type diet. Evidently once you start making KS you tend to keep making them. I have passed a 5mm and had to have lithotripsy on a giant 12mm one.
The real key to long term control is to loose weight.
I am 90# lighter than my heaviest weight and keep the complex carbs ~20% or less of daily intake, Limit simple carbs to a single treat, ~ 20-30% lean meat protein mostly poultry, fish 20-30% fats (olive oil, avocado oil, butter and a little coconut oil) the rest must be Vegetables and whole fruits and berries.
I cheat but not too often because life ain't worth living without a baked potato or fries or sourdough bread. Quinoa pasta is easy on my BS but chinese style sticky rice sends it up to 180 for many hours.
My last A1C was 5.7 only using metformin and has been under 6.2 for the last 3 years. I used to have 9s 10 years ago.