This is probably old news to most people here, but I have only recently been using this technique heavily.
I do a lot of live recording of 2 - 16 tracks, tracking during the live performance and then mixing later. In the ideal case, when I get to my Cubase studio, I can find a mix that works for all the songs recorded in the show. That’s the ideal case. In the real world, there are always variations throughout the program. A singer might get very tight on a mic at one point and not so close at other times, for example. A woodwind player might alternately use the same mic for alto sax and flute. Many variations.
For years, my workflow was to try to get a good average mix, then use envelopes extensively to deal with the variations. Envelopes work well for what they are designed to do, but most of my adjustments are rougher and don’t really need the tedium of envelopes. Another drawback with envelopes is that once I add an envelope, I can no longer use the motorized faders on my track surface for overall mix adjustments, because the faders move with the envelopes.
For my kind of project, a much faster workflow for those varying tracks is to use alt-click to split the problem tracks at key points. Then I can simply use the event-level volume handle and the job is done.
Two examples from my latest project:
The singer was only on 1/3 of the tunes and within each song, she sang only about half the time. With a few quick alt-clicks, I can separate the sung verses, and then delete the sections where she isn’t singing, reducing the mud in the mix. And then it is really quick to adjust her level on each chorus if necessary.
There was a harmonica player. I had a good level, but for some reason, on the last tune he was about 10 dB hotter on the first verse and 13 dB hotter on the chorus. A couple of alt-clicks and a quick drag of the volume handle on the events fixed the problem.
I know this is simplistic, but for me, this is way faster than using envelopes, and it does exactly what I need in 95% of the cases.