Just catching up with this thread, and your results are impressive to say the least.
Stick with it, you are doing brilliantly!
I notice a few threads appearing about chasing Hba1c, and low BG.
The only numbers that matter are the ones that suit you.
Personally, I hate being in the 4's, if I working I can really feel it, and usually stop to eat when I go below 4.5 or so.
I test my fasting at random, I like my liver dump to get out of bed with, it wakes me up.
Then it'll vary depending how late I test.
(I don't keep snacks by my bed to fool my liver, I don't make testing the first thing I do every day, just to beat the rise that will happen. That's just fooling me.)
I also like my liver dump, as when I'm working or playing hard, it keeps me going, if I use it properly.
As to chasing Hba1c. It's is an average, sometimes your BG is up, sometimes it's down. If your Hba1c is massively low, it has to mean either it's wrong, your BG never, ever varies, or you're skirting very low BG a lot of the time.
For me, I'm comfy in the top end of normal for BG, and that also puts my Hba1c in the same region, which works for me.
Fasting, normal, 3.9 to 5.5
Up to 7.8 mmol/L (140 mg/dL) 2 hours after eating
Hba1c - Below 42 mmol/mol (6.0%)
So, listen to your own body, it'll let you know what it wants, and you certainly seem to be getting it there!
Congratulations once again.