@AliceD hi Alice.
so that is a really good standard deviation and something to be proud of. I find that if I want rock solid blood sugars, with very flat postprandial spikes, I just eat low carb. It follows from the law of small numbers (small numbers mean small mistakes - large numbers large mistakes). Limiting carbs and satisfying my appetite with medium fats/proteins keeps a fairly steady blood sugar if I can keep activity and exercise consistent. That being said, I do get hankerings for Chinese food, pizza, beer and like that & etc. so I am not always on a low carb diet.
if you are able to keep your blood sugar that steady I see absolutely no reason why you can’t have any hba1c you want. how long have you been at 7.1% ? what are your overnights like?