Black Cube question

[¬Rob]

Alright, I'm the kinda guy who buys NX maybe once every few months, if my bills and real life expenses allow it. Because of this and coupled with the fact that Legendary rank has a lot of garbage lines on non-weapons, I stick with unique as the highest I go for(except on weapons of course), I don't care how much I'd lose out on. Plus it'd irritate me to hell and back to check my equips and see all gold, and some green mixed in the outlines of my gear.
But as of the RED update, the only NX cubes available both go to Legendary.

I'd like to know if Black cubes can stay unique if they land a legendary reveal. It'd be easiest trying with 100% rank up items, rank up to unique with occults(RA boxes still give them)/Craftsman cubes to unique, then 1 black cube.

If they can't keep the unique rank, I'm probably going to... just not upgrade once I hit unique. (Also I realize it would probably just be cheaper to deal with legendary, since the RED cubes cost as much as original cubes do. I'd like to know, whether I decide to or not.)

Thanks in advance(if this even gets answers)!

[Marksman Bryan]

Black cubes can keep unique rank during a rank up (the box that pops up is extra "flashy" when you rank up, and you can choose to keep unique).

Although, apparently RED cubes have such a sh'it chance of going legendary you'd probably be safe if you used a few.