hba1c correlation with RBC lifespan

[Bluetit1802]

I am very interested in this because my HbA1c results are far worse than my Libre 1/2 results predict.
The Libre tends to be near to a finger prick

That is exactly what I found when I was using a Libre. However, my Haematocrit levels have always been at the high end of the range. Over the last 8 years they have ranged between 0.40 and 0.46. My RBC and Haemoglobin are more or less in the upper half of the range, so the opposite of yours.