Hi Bert,
I've had a listen and a 'look' at Phil's Derwent song and there really is no easy way to increase the overall volume. If you do wish to do so, then you will have to increase the volume settings for all the parts in each of the Panel Memories. I also noticed that Phil uses 'dynamic' volume changes in some of the parts, while the sequence is playing - you will see these changes in ACP1 and ACP3 when viewed on the 'Home' screen, while the sequence is playing. These changes over-ride the settings in Panel Memory and are incorporated as 'events' in the particular Accompaniment tracks. I expect that Phil made these 'dynamic' volume changes during his final balancing of the tracks.
If you would like to know more, why not contact Phil - his email link is on his page..........