In short :

Though it is likely designed as a mastering tool it is extremely effective to get almost any tracks clearer in a mix with a very few and short adjustments, so in term of workflow it can be of an enormous bargain, ...and an absolute no brainer being free.

To be honest i never had myself on that purpose much use of both "character" knob and "normal/fast" switch, but both maximise and output level have been well enough for me and it tend to replace any compressors on separate tracks as the useful adjustments just take a few second to achieve .

Maybe a rough technique for some, but i just can strongly recommend it, if for instance, your time is limited and need fast ans satisfying results for track's signal level and mixing equilibrations.