Hello, you are referring to the Android version, right? Eventually we will add more buttons in the interface to allow for quick undoing and redoing, without you needing to go to the Edit menu and undoing from there. We'd also love to also add gestures for this, once we figure out how to implement them. As for drawing only with stylus, this will also be hard to do, as we'd most likely need to make our own system for this, as I don't think Godot (the engine we use to develop Pixelorama) has any way to differentiate between stylus and finger. We will definitely work on these issues however before the Android version is considered ready to use.