I was just thinking that it would be nice if Dorico could take the work I do in creating the left side Master page and automatically generate a “mirror image” for the right side. Then the user could simply make any tweaks if necessary to this automatically generated page. The current practice of drawing text frames, music frames, and graphics frames twice can introduce variations in the size and placement of the frames from one page to the other, as well as taking the extra time to input these items TWICE.
I think that in most contexts, the page # will be one item that will be “mirrored” to be justified left or right. The user would still have the opportunity to override this as needed.