Vaal Fireball + Fury Valve

I don't think Vaal Fireball is working properly with Fury Valve.

Fury Valve is supposed to allow the firing of base projectiles which then split based on number of extra projectiles. This is how it works for the other skills I tested. With 2 extra projectiles from Fury Valve, Spark fires 4 projectiles which then split twice. Same mechanics with Barrage too.

However, Vaal Fireball fires one fireball which then splits into 33 projectiles. Vaal Fireball's projectiles are not defined as extra projectiles but base projectiles. Therefore, I think it should fire 32 projectiles which each then split twice.

Or I guess the gem description could be changed to state + 31 additional projectiles.