Your comments
There is now a demonstration of this via PowerShell here:
https://ketarin.org/forum/topic/3947-creating-new-application-job-variable-with-powershell/
No. The PreviousLocation is preserved as a complete path and only the file that exists at that path is compared with the previous version, if it's missing or that path doesn't exist it redownloads it even if the constructed path (including variables) exists.
This is where the Wiki is useful:
Customer support service by UserEcho
It would also be nice if there were a means of clearing the log other than closing and reopening Ketarin. Or a way to limit the active log size.
Sometimes I will have to wait 20+ minutes for the log to finish displaying after I open it to troubleshoot a single app.