It can. I have a personal sharing. My father got into an accident last year with broken leg bone and diabetes complication with blood glucose reading of 20.9. His surgery wound is able to heal within 1 month.

4 months later, his blood glucose level is able to be reversed to healthy level of 5.6 and no longer need to take diabetic medication and insulin shot

Probably you can enlighten us your definition of borderline?
My father is a confirmed diabetic prior to the accident. Just out of curiosity, do you know how insulin or diabetic medication actually works to lower blood glucose?

Stimix, which type are you?

As what I know, T1 is due to some people were born with pancreas that is not able to produce insulin (heredity). While T2, the pancreas is able to produce insulin but not all insulin were used/or not enough. Thus, insulin shot is given to people with T2 diabetes. But if this continues, the working pancreas will not produce normally since there are supplies from outside. I believe this is why your doctor not able to diagnose your type. Sometimes tell you T1 sometimes T2. Doesn't sound reliable to me

For my father case, luckily we managed to get good reliable consulltation. Instead of depending on insulin shot for whole life, my dad opted for supplementation for healing (using complimentary therapy). So his T2 diabetes was reversed in just 4 months and now even without insulin shot/mediation, his blood glucose reading is 5.6