Thanks for the confirmation Acorn.

I agree completely with your suggestion on using layers for hidden objects, but I could see how someone might end up in a soft-group tangle with this bug.

@gcellison

Long story short… apparently, the software cannot ignore a placeholder that contains an external image reference, even if it is hidden. So, they continue to show up in the preview even when made invisible in the project.
You could place the geo-reference placeholder(s) on their own layer for each page. Where you wanted to have them appear individually, they would be on their individual layers. When the layer is hidden they should not appear, when visible they should.

I would have thought this should work.