Galvanic Shards Various Projectile Interaction Questions

I'm trying to learn more about how different projectile interactions work with galvanic shards and the beam associated with it:

1) Chain: The passive node Branching Bolts adds a 60% increased chance to chain an additional time for lightning skills. Does this work with Galvanic Shards? Will each projectile effectively create 2 chains if there are mobs to chain from? What about Chain from terrain? Is it the Projectile that's chaining, or the beam?

2) Projectile Count: Galvanic Shards shoots 6 projectiles as base. Additionally, 1 projectile is listed under "beam". How does this translate into chain count? If we equip scattershot, 8 projectiles are listed as base, with 3 projectiles listed under "beam". Does this effectively triple our beam count per projectile fired, or only add 2 projectiles to the base attack?

3) Pierce: Is a "Beam" created when a projectile pierces an enemy? I know "Chain" cannot occur when piercing, but the projectile itself isn't chaining, it's instead creating a "beam" that chains.

4) Fork: We split our base 6 projectiles into 12 when they hit an enemy. Does this effectively allow 18 "beam" chains per shot baseline with Fork, with 12 being 50% less damage?

Is there a good way to test this?

Thanks Exiles.

I have some of these same questions and haven't been able to find a good breakdown. Can anyone that understands how this works kindly take a moment to explain, or link to a video or wiki that answers some of this? I know how some chaining mechanics work in POE 1, but not sure about this game.