Hello!
I am using the iOS app, and I believe it would be great if the Apple Pencil 2 Double-tap functionality could be used to switch between different annotation tools (e.g. pen vs highlighter, pen vs eraser, highlight vs underline etc). Ideally, users could select which tools they would like to switch between 
Thanks!
Thanks for the request, @alk15, and a very delayed welcome to our forum 
I’ve added your feedback to the topic on our internal tracker for the team’s consideration. Better support for Apple Pencil / general stylus functions is becoming a popular demand, so hopefully we’ll be able to develop more solutions for that soon.