Thanks for taking the time. My current project is about 1600 pages total, structured as a book comprising about 20 separate documents. I don't see a way to avoid this "empty frame added" issue in such a case when I need to make a revision to an earlier chapter.
In I've sense it seems like maybe a unique case. I could, for example, design it such that a new chapter always begins on a recto page, but that's not what the client wants. There are other occasions where this issue arises in which I could rethink my approach to avoid ever allowing a recto page with a primary frame get pushed to verso.
I feel this discussion has gotten into the weeds of linked threads and reflow options, which are really irrelevant to the issue at hand: that when a recto page containing a primary text frame gets pushed to verso for ANY reason, a blank frame gets added behind.
If you have not encountered this as frequently as I have, I have to ask what I'm going that is causing me to need to add pages mid-documenr, thus causing the cascading shift from recto to verso.
One cause is certainly the choice to start each chapter in a new story. But I would rather not have to worry about going back to reapply parent pages.
I feel this discussion has gotten into the weeds of linked threads and reflow options, which are really irrelevant to the issue at hand:
Yes I think that’s right, what you are seeing would happen with any overridden Parent/Master page items.
Here I have a Parent/Master Page Item on each page of the spread, and Page Item labels on the 2/3 spread

If I swap the spread pages without overriding the parent/master page items I get this:

If I override the parent page items and move them they become page items, but are still associated with the parent item.

Here the pink frame on the right page is still associated with the pink frame on left parent page;

If I change the fill color of the pink frame on the left parent page I can see the association:
