Besides the obvious need for a multi band compressor for mastering purposes, how about a Harmonic Exciter like the one in Isotopes Ozone 4 plug? That would be even more awesome. It can really add some good stuff to a mix.
Came here to say the same thing!
A Harmonic Exciter.
That would be welcome.
Instead of a dedicated exciter plugin, I think it would be better to add some exciter-type distortion algorithms in Saturn 2. Ideally "excited" could exist in parallel with "subtle", "clean", "warm" and "broken"/"old", as additional variations for the tube, tape and transistor algorithms.