Falling Thunder

I’m planning to play a Falling Thunder build and wanted to ask people who have played it before.

I have a question about how Falling Thunder scales with Power Charges, specifically how the “consumes Power Charges” multiplier works. At 20% quality, there seem to be two possible interpretations, and I’m not sure which one is correct.

Case 1:

With 5 Power Charges, Falling Thunder gets 450% more damage.

When increasing to 6 Power Charges, it becomes 520% more damage.

So going from 5 → 6 Power Charges is only around ~15% more damage.

Case 2:

Each Power Charge is calculated independently, giving 70% more damage per charge.

If it’s Case 1, then because I’m planning to use Ailith’s Chimes to generate Power Charges (which caps at 5 per proc, and getting the 6th requires extra setup), I probably won’t spend 3 passive points just to get one extra Power Charge if it’s only ~15% more damage. That would also let me save one Dialla’s Desire.

I suspect it’s more likely Case 1, because Case 2 sounds a bit too OP.

I also have a couple of additional questions:

Does Fist of War Support apply its damage bonus to the projectiles created by Falling Thunder?

When casting Falling Thunder once, does it count as one melee hit + one projectile hit, or how exactly are the hits calculated?

Thanks in advance