Yes, it's true. I'm far too lazy to arrange these into something easier on the eyes. So here you are - a tower of discs.
Some Demonstration Discs were released with serial number variations - Treasures of the Smithsonian for example - data matches. A Visit To Sesame Street Letters has a title & serial variation - data doesn't match. So far I have found that White Label Demonstration Discs largely match some iteration of retail release - more dumps are needed (both retail and Preproduction) to paint a clearer picture.
I'm collecting my Preproduction scans here on archive.org. I hope to add more as budget and lucky finds permit.