Sophossetup.exe automatic installation fails when source is too old

I've noticed that the sophossetup.exe "ages"  which means after a while its not possible to install the downloaded setup anymore. For some customers i now made a script to download the executable every week with powershell from their tenant but since we are switching to BigFix to distribute software i want to use the blank Partner installer with the corresponding commandline switches from the CSV file.

 

now my questions is the partner setup cant be downloaded without login in , so thats impossible to do unattended. So does the blank installer "age"  also or can that be used always after downloading it?