I think you're basically onto the solution - Advanced Export by default populates slices in "Individual Layouts" that represent all scenes for just that particular layout. If you check those for export, you'll get pages that are layout-specific. Code in the head can then change the location.href based on the logic you want to go to the other page.
The issue with this approach is that you'd need to do a full load whenever the sizing changes, and possibly preserve some state for which scene was loaded and even where timelines/symbols may be at.
It sounds like you may have worked it out in the other thread though?