Hi, you seem to have been through the mill recently.
I don't think there's any doubt that stress - ie high levels of adrenaline and cortisol - stimulates the liver to increase blood glucose levels. It's described in the standard reference books - eg Bilous and Donnelly. The CGM graph attached shows one day where the wearer didn't eat anything but had the news that her son was in a car crash, then visited him in hospital, then had to call at the police station. The peaks in BG from around 2pm are fairly clear.
I've never seen any work on HbA1c results that show that overall higher stress levels lead to higher HbA1cs, but it seems logical that sustained higher blood glucose levels (whether the glucose comes from food or from an over-active liver) would increasingly glycate haemoglobin in the same way.