I've honestly never heard of anyone using it for priming sugar, though usually speaking, a pound of invert sugar should still be, ( for all intents and purposes), equal too a pound of sugar. so.......
I never heard of it either until a head brewer informed me of a few changes to try for my oatmeal milk stout. He sent me a gallon and want to try it but he never homebrewed before.
I agree Bootsy, a pound is a pound is a pound but I always went by volume when I bottle not weight and there is a fraction of priming sugar in a cup measure that is air space. But weight is a good way of trying it.