TL;DR summary:

1. Kinetic Fusillade and Kinetic Fusillade of Detonation have separate limits of floating projectiles per gem, rather than per skill or even per set of links.

2. This means you can have multiple gems of KFoD detonating over the same period of time.

3. Kinetic Fusillade of Detonation has a base time between projectiles of .15 seconds - nearly perfect for CoC.

This means you can have multiple CoC setups going off at once via multiple links of this gem.

---

I wanted to finish this build before writing a post, but real life be real-life-ing, so this is three pieces of tech and a half-finished build concept in a trenchcoat.

So I was running my Poet's Pen Lightning Warp Kinetic Fusillade Sacred Wisps build, trying to figure out what would be the best way to make resonance happen for Unholy Trinity Support, when I realized that the fastest way to do it would be another set of Kinetic Fusillade links. This led to the discovery that separate KF gems don't interfere with each other's projectile limits, and the overall discovery that KFoD seems like a decent CoC facilitator which can overlap itself.

Here is a demo showing multiple CoC setups all proccing: https://www.youtube.com/watch?v=Gcx7j03cNIs

Here is a demo of what a map could potentially look like: https://www.youtube.com/watch?v=mZc8e178LAE

And here's a PoB of what my character was wearing in the second video: https://pobb.in/q17RhC7RDdr0

In the map, I'm using Creeping Frost and Forbidden Rite because those are the skills which I know can multi-hit creatures. I am not using Unearth because it requires The Fledgeling to multi-hit.

My chest link has two separate KFoD gems so they can overlap, and Soulrend of the Spiral and Spark of the Nova because those seem like decent clear skills which benefit from more projectiles. Basically, if you don't need to deal damage, you alternate KFoD every 6 or so explosions so you never stop using them.

I used those skills because I thought Soulrend and Spark would end up with enough of a damage range to keep Resonance full, but that clearly is not what happened.

A real build would probably use either 2 or 3 CoCs going simultaneously, since maintaining uptime on overlapping CoCs requires a bit under 5 projectiles on your KFoD per CoC you want to have going. This is where the 3.8 number from the title comes from.

A real build would also probably use cooldown reduction and reduced duration to tune KFoD's hit rate, rather than grabbing the 10% increased duration node to hit a "good enough" sync between CoC and KFoD.

A real build would probably also be a Saboteur or Deadeye or something like that.

Given that this tech frees you up to do stuff while your CoC setups are blasting, I'm sure that other people can come up with other things to do with this, even without the craziness of a Diamond Shrine belt which I assume will be much less common next league.

I hope someone else can take this stub of a build and do something interesting with it!