Reduced Mana Cost from Unveiled and Rolled Flask

Hi, I have two flasks with reduced mana cost.

One with reduced mana cost that was unveiled onto a legacy Cinderswallow urn.
This one has the "of the Order" suffix, reducing mana cost during flask effect by at least 20%.

I have another flask that was rolled.
This one has "of the Arcanist" suffix, which reduces mana cost during flask effect by at least 20%.

Normally, flask suffixes do not stack but shouldn't this pair of suffixes be an exception? The unveiled craft can be crafted onto any flask while the other one can only be rolled on mana flasks and hybrid flasks.

Path of Building, which is by no means correct, indicates that both reduced mana cost effects should apply.

I just wanted to confirm Path of Building is not correct.

these are same mod group, and same mod group flask mods do not stack.

I see, thanks for the clarification!