I had the opposite condition, HbA1c 104 and Ferritin over 1,200 at diagnosis of T2 and hemochromatosis. I was told the only way to get Ferritin was by venesection (blood 'doning' each month). However the venesections did not start until 4 months later. By then my Newcastle diet had brought the numbers down to HbA1c 35 and Ferritin just above 600 (about half). The Hepatologist took full credit for the Ferritin reduction, even after I pointed out the reduction.
My impression was that little is generally known about the all factors contributing to Ferritin levels. That was confirmed when I read some researchers now think Ferritin plays a role in the immune system. I'd be interested to know where you read that low Ferritin can affect Hba1c.
If I were you I'd take your HbA1c and Ferritin levels as independent of each other until a clear relationship is established and measured. What has become clear is that HbA1c in the prediabetic range indicates accumulation of fat in the liver, and dysregulation of glucose, lipids (fats) and probably other things such as iron as well (i.e. Ferritin high or low).
The only way to treat fatty liver is by diet to lose up to 15 kg or more, maybe less at 43. AFAIK no one seems to have researched the numbers, despite estimates of 25%-33% of the population having a fatty liver. Anyway to avoid all the nasty consequences, dieting to get HbA1c down to the mid 30s makes sense.