I read somewhere that damage starts to occur at levels ove 7.8, not sure where, it may have been Jenny Rhul's site blood sugar 101
https://www.bloodsugar101.com/
I would not be happy for my levels to be up around 9mmol even at the 1 hour mark.
You mention low Gi stuff, a quick Google for low Gi gives you results like bread, brown rice, raisins, lentils, oatmeal, pasta non of which I would consider to be low carb and are definitely on my foods to avoid list.
Are you sure your diet is as low carb as you think? What sort of levels do you get before you you eat?
It's the difference between the before and after results that tells us how that meal affected our level.