The second generation of Apple pencil 2 enables user to double tap the pencil to switch between the eraser and the current tool. The feature works very well in other notes app, but it doesn't work in Onenote for ipad.
Update on 1/3:
It has been 3 months and the team did not make any progress on the issue. I have switched to Goodnotes and found it really helpful. Hope you guys find your favourite note-taking app!