Sugar Replacement Bulking Agent for Non-Sweet Hard Candies

Looking to make hard candies that are neither sweet nor contain sugar, I want the equivalent of lemon water to a soda.

I've been looking into how this might be done, i.e., what could be used in the hard candy process that maintains the resulting "glassy-ness" without too much sweetness and without spiking blood sugar.

Lactose and Allulose are the two candidates I've settled on, leaning towards the prior.

I've never tried to make hard candy, and I've only done a bit of reading on the process. I'm wondering if using lactose as a 1-1 replacement for sugar would be fine for most homemade hard candy recipes, or if there's anything else that might be a better replacement. I'd also likely be replacing the corn syrup with glucose syrup.

I don't know why you have decided on lactose. The normal way to go is to use isomalt, which ends up being most similar to standard sugar candy. (I personally wouldn't be able to tell the difference by taste, feel or appearance, but I'm not much of a candy tasting expert).

Whichever sugar you choose, you can't keep using your recipes. Candymaking depends on the physics of table sugar. Nothing of it will fit with the physics of a different sugar. You'll have to use different recipes, developed specifically for whichever other sugar you choose. Which also points you to isomalt as the better choice, since it will be much easier to find recipes for it.