V-Vocal Track, Now want to adjust Gain

I just used V-Vocal for my first time. This tool rocks! But now that I've corrected some pitches, I want to go over some clips in tracks and adjust the gain in certain areas of the clips (not full track). But I noticed when I use envelope tool to select areas with nodes and adjust decibels there's no difference in output. Then I tried to select the area that I wanted to raise gain on and tried Process -> Audio -> Gain, but all options are greyed out. How do I make it so I can use Gain tools on my clips that have V-Vocal on them?