The problem is that difference maximums apply to menus rather than timelines.
An alternative is to put the video as a motion background to a menu. Like your still image version, you have a single button, and advance to the next menu (still background or motion).
BTW, the button does not have to be large; it is a single button, and as the default is always active. So "enter" on the remote will select it. On a computer, it would need to be large enough for the user to click it.
Encore is a single VTS system, and long "slideshows" done like this will run out of resources, perhaps before the maximum size is reached.
Scripting, which encore does not have for DVD or Bluray, would give you a better option.
