Another thing I've found useful to adjust Volume Envelopes rather than Offset mode, is to select the whole Volume Envelope, and drag the whole volume envelope level all at once.
In Track View, with the automation lane turned ON, there is a "sweet spot" just to the left of the automation read button (R). When you click in the blank space there it turns red, and selects the whole envelope.
Then, while holding the SHIFT key, the entire envelope can be dragged up or down in small increments. (Using Select tool, not Smart tool)
Even better, if you turn on all your automation lanes, and select multiple tracks using that "sweet spot" (by holding down Control key) . . . multiple Automation Volume Envelopes can be adjusted.
I use this quite often, when I need to tweak the levels of tracks after volume envelopes are already in place.