Nice work. I have a few observations and a theory about how it can surpass this but it’s all numbers and ideas, so I have doubts about it translating well to practice.
First, notice how anything that is away from you simply melts in the video, pay attention to when Agnidox knocks you back in Rift Guardian fight; that is the effect of No Escape passive. Secondly, you always go in the middle of monster crowds to inflict Area Damage which is not wrong in any sense, but your edge is at keeping the distance; try not to be in the midst of monsters, always scoot to the outer edge of any monster crowd.
My suggestion is ditch the Cindercoat and move Aquila as an equip from the Cube, then replace armor slot of Cube with Strongarm bracers. In theory, considering you have other sources; the additional elemental damage of Cindercoat is a mere 11-12% increase by margin, while Strongarm is 30% increase as a unique multiplicative.
This boost should help you use Ground Stomp more often but in return you may run into problems about crowd control immunities. Good news is, Strongarm debuff works against crowd control immune targets; only thing that matter is an attempt have been made for changing position of the target.
Lastly, my theory starts with questioning the viability of Stricken here and I wonder if changing some skills and items around would result in better performance for this setup. As an alternative, you can replace Stricken with Zei’s for a straight damage boost but in that case I definitely suggest you to replace Ground Stomp with to Revenge- Grudge, or Charge with Leap- CoA to feed into No Escape passive. You need to pull monsters then move away or knock them away.
Since Rift Guardian fight could take you longer without Stricken, I reckon you also need to go back to Squirt’s with this setup hence you’ll need Threatening Shout- Intimidation; Falter skill rune removes the damage debuff.
You never shown the passives you have picked, but I get that you have; Ruthless, Revenge, Berserker’s Rage and No Escape on HF Amulet that can be easily pushed as a fourth passive.
I don’t mind but I don’t think this would happen. If anything this sounds like a cause for fans outrage about a “pay-to-win feature”. When Altar comes to non-Seasonal as a paid feature, people would rightfully demand Leader boards to be split as well. We don’t know the exact reason why they haven’t brought Altar to non-Seasonal yet, but potentially it can be about how much paragon level the player already accumulated there.