It looks like you can scroll to the top by tapping the red title bar.
The red bar is gone in full-screen mode so it's one or the other; full screen or scroll to top.
I would love it if shake-to-undo undid this. Hate when I tap it accidentally.
you never shake your phone accidentally?
Shake to undo always prompts for confirmation to undo the last action. Touching the top of the screen to scroll to the top of the page does not ask for confirmation, which is a pain when you are 3/4 of the way through a very long article.
Thus, being able to shake to undo the action of auto-scrolling to top of the screen would be a nice solution.