I don't have any personal experience with Prozinc, but there are several very experienced members here who will be able to help you with dosing if needed.
@Sue and Oliver (GA) is one of our most experienced Prozinc users.
One problem with fructosamine tests is that they show an
average glucose level over a period of time. By testing at home, you know where the numbers are right then and there. That's important if you're dealing with a low numbers/hypo situation. Some vets discourage home testing for whatever reason. (My first vet wasn't in favor of it.) Without testing at home, though, I would have never known that Jersey's pancreas was healing and that she no longer needed insulin. In fact, I would have overdosed her right after diagnosis.

Anyway, I really encourage you to consider home testing, even if your vet isn't in favor of it. If you need help getting started or just want additional info about it, give a shout out. The individuals here will have tons of tips and tricks to help you get started.
My (first) vet put Jersey on Hill's w/d prescription diet to start with. I later found out it had just as many carbs (in the 30% range) as the Meow Mix I had been feeding her. After that, I started trying all kinds of low-carb canned foods. Unfortunately, with 6 mouths to feed, we couldn't afford some of the more expensive brands.....and she didn't like them anyway!

So, we ended up feeding a variety of low-carb Friskies pates and Fancy Feast classics. I've just recently started making the switch to homemade. Have you seen the low-carb
food list that many of us rely on when choosing foods? Ideally, we're looking for foods that have less than 10% carbs.
Hope some of this info helps!
Shelly