Allow the creation of slides which "build", like PowerPoint's "appear" animation, without making multiple pages.

I am a university professor; my colleagues and I use GoodNotes heavily both for teaching and presenting our research at scientific conferences. One of the last advantages PowerPoint has over GoodNotes, for our use, is the slide animation feature, where objects on a single slide can be made to appear one at a time when the slides are presented. To replicate this behavior in GoodNotes right now, the standard technique is to build the slide over multiple pages, using the page duplication feature. However, this is cumbersome and makes the resulting slides very painful to edit (edits on one page don't show up on the duplicates).

PowerPoint contains many fancy animation options, but personally I'd be very happy with just the "appear" animation.