What is the problem with adding functionality to change the buttons to actually do what you want them to do? I’m happy with the page scrolling function. Beyond that, on my mountain bike, the other two buttons are useless. By all accounts very few people use the lap button and I would imagine no one on a casual muddy mountain bike ride would.
if I could choose I would have the other two buttons zoom in and out of the map. Is this really such a far out idea?