…and when the Sorter is launched at login, it opens properly. But when I manually launch the DEVONthink Sorter file, the DEVONthink application opens instead.
I thought this script would help, but it launches DEVONthink first before activating the sorter.
You could show the DEVONthink app package contents in the Finder (Right-click>Show Package Contents), navigate to the Sorter’s location (the path that you posted above), make an alias of the Sorter, and place the alias in your Applications folder. Put the alias in your Dock or launch it as you do any other app.