Ball Lightning spell classified as Projectile but not forked with Mana Tempest

Ball Lightning spell is classified as a Projectile type spell, however Mana Tempest doesn't seem to fork the spell, even though the Mana Tempest spell specifically states that "Projectiles from Empowered Lightning Spells fork ". Is this intended behavior, and thus the Ball Lightning spell should not be a Projectile type spell, or is it a bug?

I imagine it's because the main Ball Lightning always Pierces. From the Fork help info: "Projectiles that Fork split into two the first time they hit an enemy and do not Pierce it."

The skill should specify that the main ball always pierces. Feels like an oversight.

Another possible oversight is that Fork Support can be socketed, yet does nothing, since its projectile always Pierces.

To top it all off, Chain can't be socketed into it, which would actually do something, for the bolts of lightning that shoot out. Since projectiles can't Chain from an enemy they Pierced (per the Chain help info), the main part of the skill would not interact, which is fine.

So the thing that doesn't interact is socketable, and the thing that interacts is not socketable. :P