[Waldbaer]

... I could also consider allowing the actions for the sides to be something that can be changed under Settings->Touch & Pedal Settings->Touch Actions. I wanted to avoid that just so there is consistency with some of the base functionality between all users, but some users might appreciate being able to change the tap actions for those areas, particularly if they use a pedal to turn pages (or want to only swipe to turn pages but have the tap action be something different).

Mike

This sounds like a nice idea to me, too. I think you should be able to remember if you changed the Touch Actions anyways. As a brass player, I prefer to vertically scroll pages, so the page turning is not that important for me, too; maybe two additional Touch Areas might be more handy.
Long story short: +1 for configurable left/right areas from me.