But it would be all after the fact, on the Master, at least they way I think about it. It limits the Master Output and brings every rig to the same volume by measuring levels at the Input stages and before the Master stage... or something like this. I'm no expert
Something like Fractals 'unity gain' feature? When different loud guitarsignals played over the same settings cause different outputvolumes, then there is no same volume for us all. Unity gain does not even out all volumes, how else could you play softer or harder on your guitar, all dynamics would go lost. When we can influence the resulting volume just by our playin, and all sounds have a different amount of compression, than a same volume for us all can not exist. We could get near for an average player with an average guitar...so someone needed to measure how this average loud player plays.