The Level parameter automates within the track’s volume fader range. The volume fader can be set to a maximum of +12dB. Set the fader above 0dB to get Level automation envelopes to act on the gain to the desired degree.
This method is, arguably, more convenient. That is, to set maximum gain and control volume below that ceiling. Reason being is that 0dB on an envelope with default range with +12dB maximum would be difficult to snap to.
Another option is to adjust the gain on the sound events. If there is a pause between your sections you could split the sound event and increase the gain on the solo part. Even if there isn’t a natural pause where you want to split the event, you could still do the split, overlap the events slightly and apply crossfade to fade in/out the gain change.