I edited one page of a multi-page Acrobat Pro DC PDF (created by exporting from InDesign) by removing a rule from the top of one page using "Edit PDF" (I clicked on the rule, then deleted).
In the original InDesign document this rule was on a master page and was applied to nearly every page. When I deleted the rule on the one PDF page the rule was, to my shock, deleted from every other page in the PDF as well, not just to the one page I was editing. In InDesign I would expect an element deleted from a master page to be removed globally, but it seems wrong, and potentially hazardous, for an edit applied to one page to be applied globally.
If I need to perform a similar edit in the future I'll give "Edit Object" a shot.