Hey again! I chatted with the product owner overhauling our exporting process. We’re knee-deep in that work right now, and to keep our eye on the prize, we aren’t planning to include the online version URL for now. We’ll take a second look at what work this would take after exports are back in shape.
We recently updated our "Compare Mailings" export, and good news! The online URL is now included as a part of this export. I'm going to mark this idea as implemented. If you have any questions, please let us know.