"Watch How I Do It" doesn't buff Artillery Ballista

The Artillery Ballista skill gem uses its own weapon, so it does not scale off player's weapon. Expectation is that "Watch How I do It" would buff the Artillery Totem because of this, and the fact the tooltip says "allies" which is a category applicable to totems.

The tooltip damage does not increase when allocating "Watch How I Do It". In addition, there's no observable damage change when using different weapons.

Steps to Reproduce:

1. slot Artillery Ballista in gem menu (G)
2. expand details pane to show damage for Artillery Ballista explosion
3. Note the explosion damage
4. Allocate "Watch How I Do It" ascendency passive
5. Observe the Artillery Ballista explosion damage on the skill details pane -- the damage is unchanged.

"Cannons Ready!" passive does affect the tooltip damage for Artillery Ballista. So I assume the tooltip is implemented correctly and it's the "Watch How I Do It" passive that's not applying 25% of the main-hand weapon damage.