Explosive Concoction of Destruction isn't working with Trinity Support

I tried multiple setups without more damage and have come to the conclusion that the added damage from the flaskes consumption effects just don't work so it bricks trinity. Hope it's just user error but noone else is using this skill as far as I know so kind of can't double check with other people.

To get fire resonance, your highest (elemental) damage type must NOT be fire. This is quite difficult with Explosive Concoction since the inherent fire damage outmatches the cold and lightning damage so you'd need to have other sources of lighting or cold damage. I believe lightning is preferred because it has a high maximum, so Wrath for example might add enough to occasionally cause more higher lightning than fire damage.

Even with auras that grant added cold and lightning I'm still having issues generating fire resonance. I even went and removed inspiration and EDwA and still can't seem to get it to proc.

So what I think is happening is any added or more damage is working on the fire damage but not on the other sources of damage from the flask effects of the skill and pretty much just bricking any interaction with Trinity which is sad and kind of makes me see why people aren't playing the skill.

What are your tooltip damage ranges for cold, lightning and fire?

Was able to yank it from your PoB actually. You do 50-416 lighting and 397-598 fire. Cold will never be higher than fire currently so its discounted. So you have to massively high roll lightning and massively low roll fire to even start to fill trinity. With the current setup it will never happen on any kind of consistent basis.

Compare the difference between the damage on the gem and the damage the auras give. Looking at your character, you'd still need max roll on lightning and min roll on fire with Herald of Thunder active.

Things like Inspiration Support and Elemental Damage with Attacks which would boost all three damage types wouldn't make it easier or harder to get higher cold/lightning damage than fire damage.

Try using "Added Lightning Damage Support", and see how that goes.