Suggestion: Have the “Home” button scroll me automatically up (e.g. like Page Up does today) AND left (something I have to do via a mouse today).
For a variety of reasons and from time to time, my mockups are scrolled right and down. I’ve got a use-case where sometimes I just want to scroll them all the way to the top and left so that I can click through them in sequence and double check that I’ve covered all of the interactions/comments I need to.
It’s really frustrating to have to use my mouse to click in the small area of the scroll bar to scroll left. The Page Up button handles the top scroll so nicely.