I believe that the sugar's main purpose is to moderate the taste of the salt and add flavor. I have a recipe for bacon cured with Instacure and sugar substitute.
Bacon
11-14 lbs pork belly skinned
1c salt noniodized
4Tablespoons Instacure 1
2c honey or sugar substitute
rub evenly into pork belly wrap tightly with freezer/butcher paper and seal in plastic wrap. Place in fridge 5-7 days turn and rotate daily
wash off cure and honey, w luke warm water
soak in warm water about 1 hr taste for saltiness by frying. Dry in moving air, cold smoke 6 – 8 hrs no higher temp then 100-115
I have never used this recipe so check the amount of cure to use on the Instacure 1, cure #1 packaging.
Al