That’s a new one to me. I’ve been at this for several decades and have never read of anything like this in any patent or heard of any wax manufacturer that would add it to a blend.
hot throw is a factor of balancing your wick with the fragrance and wax blend in a given container. We work with countless variables in each component.
At first thought, I would not think a sodium derivative additive would burn well at all in candle fuel. How would it dissolve in any wax or oil based fuel? Maybe, possibly it could dissolve somewhat in some gel type waxes, but even then I’m not sure it could given sodium bicarbonate is water soluble due to it’s polarity. Wax is pretty much non polar so it would be nearly impossible to dissociate the molecules to dissolve. Wouldn’t you just end up with random grains of bicarbonate floating in the wax, likely precipitating to the bottom of the candle as the hot wax cools? The next thought is that baking soda is something recommended to extinguish fires 🧐
I have used wicks treated with sodium (cd, CDN for example), but not sodium bicarbonate in any fuel itself. The sodium wick treatment involves a dip in liquid form (dissolved in water), and the cotton wicks dried before packaging to consumers.
if you’re an adventurous type, give it a whirl and let us know what you see in your experiments. I’d start with the tiniest mount, like 0.25% or even less.