I've read somewhere that UAD trialed iLok machine authorisation with some of their freebies and for some reason it caused a bunch of problems for them so they vowed never to do that again. I wouldn’t count on them enabling it any time soon.
That library is usually Kontakt Player. Did they really make a non-Player version just for this or is this some odd mistake?
edit: seems to be an old version of the library that’s indeed Kontakt full. No idea if there’s other differences.
I actually just got this and have no real experience with any other exciters either. I'm planning on trying it instead of EQ or saturation whenever I would usually go for some kind of high frequency boost. Just another flavour.