Another 30 minutes of googling and I think I understand what you mean. The non-plex pass version is “public”.
However the download page shows 1.18.1.1973-0f4abfbcc as the public version. There’s no difference with the plex pass option turned off or even when logged out. In other words, 1.18.0 is not a available.
After much scouring of the web, i’m fairly convinced that it is impossible to download any version other than 1.18.1.1973-0f4abfbcc. (Other than the ancient version available via the synology package manager.)
