[BScout]

Volume and Volume Trim end up with the same result.

Usually we (my style of mixer) rides volume as the first pass, etc to get it the way we want -- rewriting sections as we go (touch/latch).

Volume Trim often comes later when doing mix notes. So you write/rewrite trim until you satisfy your notes -- affecting the volume automation you've already done earlier (and presented to the client.) When the new volume rides are right, you coalesce the trim automation so it becomes part of the volume automation and the trim automation line returns to unity (0 dBFs) for the next round of notes/corrections. Repeat for however many times as is necessary when going between mixing and client review.

So a most basic example is you write volume auto (and the line is all over the place) and then afterwards realize you need to bring everything up. So you lift it in Trim automation until it sounds right (you can experiment as much as you want.) And then coalesce it to the volume auto when you get it right. You never mess up your original automation until you get it the way you want. In something simple like this, you could use clip gain (which is a bit of a messy way of accomplishing the goal) or you could hand adjust the volume auto line by mouse. But Trim auto makes it easier/faster (and when it gets more complicated than just an overall increase, a god send.)

Many ways to skin this cat but that's why Trim auto exists. (some people always write in Trim and then apply to Volume vs first starting in Volume.)