I think it's great that you can have different page sizes and vertical double pages in the Publisher. Very good! 👍
Now the connecting of single pages is still missing. This would make it possible to create leporello folders, because then you can create the shortened flap page on the left or right.
This would also allow other folding variants such as zigzag or altar folding.
Another application: cardboard packaging with flaps would be possible.
For presentation purposes, a 3D visualisation could also be envisaged.