To be fair, in non T2DM populations, A1c is a tight range; its difficult to find correlations, even with causative factors, within tight/healthy ranges (independent of A1c).
Also non-T2DMs may not primarily use CGMs for A1c support e.g., personalized response, engagement, etc
If you don't have type 2 DM, please put away your CGM. Why? There is no correlation between CGM metrics and A1c in the non-diabetic population. 1/3