I haven't, but I wish I had TBH as if I'd started following it earlier perhaps I could have avoided/reduced all this stress of GD now! I'm on a Facebook group for GD mums and there is a lot of talk from people who have had GD pregnancies before about starting low carb earlier even when not diagnosed yet in subsequent pregnancies.
It makes sense to me as a general way of eating anyway I think and I plan to continue to some extent after the birth even though I don't have to. But I will have a lot more freedom for treats then as I am being really super strict now.
It's not an extreme diet at all really - I took it way too far at first (being autistic I took the consultant literally when she said about avoiding certain things) and got really unwell. But I was then told that basically all I should do is halve what carbs I have with a meal and opt for wholemeal etc, and increase protein/healthy fats, but otherwise eat normally.
I have been doing stuff like eggs bacon and avocado for breakfasts, if I have anything like pasta I'll do a small amount for me with more sauce and veg, burgers I can enjoy without the bun, that kind of thing. So in that sense it's not an extreme change at all really. It's more the snacks I have to be careful about and I am having some stuff with sweeteners in which I wouldn't normally, but it's the only way I can have anything very sweet without risking my sugars going high.
Sorry I am waffling but basically I don't think there would be any harm in just reducing carbs a bit, it doesn't have to be extreme at all and if it means you end up eating more good stuff to balance it out then that can't be bad.