Jon is currently out, so I will be taking over this thread until he returns.
Within ZoomSDKMeetingUIController, there are various interfaces that may be useful to you. You can use getWallViewPageInfo to get page info of the wall view, and showPreOrNextPageWallView to navigate through it.
Unfortunately there are not callbacks to alert of these buttons being pressed or the current state. However, you can control these programmatically with these functions in ZoomSDKMeetingUIController