I have an update planned when I get a little more time that will force all URLs in a thread to have the parent post (initial post) as the ID; this will make all pages that a share is clicked on to record to the same parent.
Example; I click "share" on page 5 of a thread, someone clicks share on page 2, someone else clicks it on page 1; all are regarded as different pages. The planned update will have all posted to the primary page. I just need to figure out the logic for each page I've recommended this to be installed on (above).