Mine scans too, only takes 3 secs so no biggy, but the toggle is in Global/ VST plug ins.
As I said I use the LP 64 multiband.
The reason is 1 channel compressors loudness maximizers like Boost11 squash the whole mix , if the bass is hot all the mix goes down with it. A multi band separates this and only the bass or the ?? will be squashed, The result is a mix that still has dynamics. It's a mastering tool so I only use on master buss.
My other reason is it quickly will show which fequencys are too hot, I can then go to the tracks and deal with it there with EQ or a individualize compressor. The end result is a nice loud mix over the whole spectrum