MacOS – How to move Finder icon location in the dock

If a menu icon is allowed to move, command + mouse select will work.

You might have to patch the program (or System Ui Server). Have you asked the developer if they can implement this as a feature?

Only the Apple icons are movable on my 10.6.7 systems so it certainly isn't easy for a developer to get this working and may be impossible in practice.

The only workaround would be to have a script that delays the radium start as the leftmost item is the last to load. If you had a launch script that slept for 3 minutes and then killed, relaunched that app - it would be leftmost until another started... If it was really important, you could kill and relaunch it periodically every X minutes to ensure that over time it's the leftmost icon without you taking manual action.

Cheekily adding this as an answer based on a comment above as the commenter didn't include it.

The cause appears to be a mystery, but if you remove the icon from the dock (just drag it away until you get the vanishing smoke animation), and re add the icon (run the app, right click on the dock icon and click Keep, or drag the icon back in from the finder) to get the full resolution icon for any app that is doing this. It's a workaround that doesn't explain the issue, but should be good enough.