The MX mice series from Logitech is a pretty popular device. It includes a software called Logi Option+ that allows per app specific customization of the mouse buttons. For me, it was a life saver when scrolling documents was not working for Mac. I was able to set one side button to scroll up and the other to scroll down (each button was mimicking pressing the up or down arrow key, respectively).

Now that the issue was solved, I am using one of the side buttons for "undo". It works great during long studying sessions when I am highlighting a lot. Not having to go to the toolbar each time I make a mistake to select the eraser and then select again the highlighter saves time and reduces muscle fatigue.

That being said, this is was just a way around that I found to make my life easier since there is no "native" options to customize the buttons like other apps have (E.g. Microsoft word, excel, etc). It would be amazing if you guys can add the ability to switch tools, color, brush size, etc.

Thank you!!