Can I uninstall an app that I moved to my external drive?
Short answer: Yes — use Uninstall on the Moved tab. It removes the app from the fast drive, the leftover shortcut and its leftover files, all to the Trash.
Yes. Click Uninstall on the app in the Moved tab. Storage Studio removes the app from your fast drive, the leftover shortcut in the Applications folder, and the app's leftover files on your Mac — all to the Trash, after showing you the list.
The drive needs to be connected so the app itself can be removed.