Basically, I really like MI-Duplicates, but they are quite inefficient if you use a spell like Blades or MM - as Mirror Images are mainly good for recasting Black Hole, Frost Nova and taunting. So, what I did was try replacing my String of Ears and Captain's Pants with Captain's Belt and Hexing Pants, respectively. I then specced out of Flame Blades and replaced it with Magic Weapon.
The result was a really synergistic combination of Mirror Images *only* casting Black Hole and Frost Nova, together with EB-Unleashed doing 25m crits on whites and 50m crits on Elites. I also specced out of my Paragon Life on Hit, which is a useless stat with just EB-Unleased as your damage dealer. This let me spec into 50% Area Damage, which is very noticeable DPS. I can now defeat T5 rift guardians handsomely solo.
Given hexing pants are a great resource cost reducer, I'm also going to play around with replacing Magic Weapon with Arcane Orbit. This could be interesting as Arcane Orbit works well with a constant-motion build like hexing pants. I expect that Magic Weapon > Arcane Orbit in terms of practical dps delivery though., but I will test.
In terms of safety, I find I am not missing Blakthorne status protections as much as I thought, as I am constantly moving and not (trying to) facetanking (unlike my old build).
Hope this gives others some things to think about.