Being able to learn a custom spectrum for Auto-EQ would be really helpful as different genres often have different norms.
i.e. the expected spectrum of a techno song will be quite a bit different than an acoustic folk song.
This is a fairly common feature useful for mastering.
Preferably there would be a strength parameter for how closely Auto-EQ tries to match the reference.
Most matching EQs only allow using a single file as a reference, but iZotope Tonal Balance allows creating a combined target spectrum from a folder of files. This way the user could create a folder of well-mixed, representative tracks to use which can even out the idiosyncrasies of individual songs to achieve better results (this usually works best with the fullest parts of tracks like choruses/drops.)
