That's correct. This can't be done via the editor alone.
There is a tutorial here on some of the intricacies of building multi-page Presentations - mostly stopping and starting Gadgets that are not currently visible so you don't consume resources unnecessarily.
There are also some best practices for building these types of Presentations.
Thanks for the conformation. Regarding additional information I am looking for;
1. Way to dispatch events from a placeholder to parent presentation. For example on a button click event I want to remove a placeholder.
2. Documentation says use onClick(id) to handle image click. But I noticed that the id is always "image" event if my presentation has multiple images. Is there a way to assign unique id through editor, or do I need to make a code change to assign unique id?