I was looking at this recently in response to this. I had looked a few years ago. It looks like you used to store a field called pgID which was a fragment of the posted URL and now you store the entire URL in a field called postID.
This seems to have happened recently. To echo Shmuel’s need, my goal is to be able to display the URL. Certainly much easier if I don’t have to build it myself, just extract it.
Would this be something that you would consider amending on post update and/or adding a support command to migrate old posts?