My saves are into v0.02.0 of the game. I don't have any saves in the other versions of the game.
Despite that, I nevertheless followed your instructions to the letter:
• I clicked on "Other Versions".
• I selected "Downfall: A New Beginning (Old)".
• Then I clicked on "Export Saves from Downfall: A New Beginning (Old)".
• I was redirected to the download page, and I clicked "Export all game saves" to download the save file (gamcore-downfall_a_new_beginning_202606010449.txt).
Unfortunately, this file is completely empty and is only 2 bytes in size. So, I went through the process again with each version of the game. Unfortunately, no matter which version I export, I always end up with a completely empty file that's 2 bytes in size.
Note: The attached file is the export of "Downfall: A New Beginning (Old)". Files exported from the other versions of the game are exactly the same as this one.