3rd reward - Dark Smugglers Cache

I think that has to be a reward imo, especially if we're talking 400k dmg per lock. The other drops are ok, but definitely not worth the 400k dmg needed to get a lock. The chance at a cache(even if you wanted to nerf it to a 4 hour cache for this elite) would get people to hit it, but without it i feel most would just leave it after they got the upgrades.
Dark Phase Engines, will sometimes phase out of dimension, making itself invulnerable for a short time (3 mins?) Almost like the Ghastius Bane Fiend but in reverse. Has a 10% chance of happening per attack, and maybe 5% with IMI on
Could be kinda OP, but without knowing more, like the rank of the NPC itself, i can't judge. I mean if it had a rank of 1800 say, then that's 4500 per shot if you cap(which most probably can't), that means it will proc at least 5x, but more than likely, it'll proc even more than that, meaning at least 15+ minutes of waiting to hit it.
I do like the idea though, it's a simple idea(in a good way) with decent items that aren't outside the realm of actual implementation.

As for ship mods, honestly the up and coming playerbase has very little use for ship mods that aren't epic, so if you do have ship mods, they better be stupid good, like the attiroth stacked plating.