Finger gestures shortcuts
Like erase with finger when using apple pencil or tap with 2 fingers to undo, double tap to add "post-it", like other apps do. It increases productivity a lot...
John Dy commented
Really need that two-finger tap to undo.
Please!! 2 finger Undo is a must!! And 3 finger redo while you're at it. Take a lesson from Procreate. They've already figured a bunch of this stuff out. 2 finger undo is becoming "univeral" in many apps and I keep trying to do it in MS's IOS apps, without much success. If anything, make it optionally enabled.
UX people like to talk about "flow" a lot but so many of the apps I use require you to go hunting for Undo and Redo (and Erase), thereby killing any illusion of "flow".