The display of the dialog trail is controlled by your operating system not by Revit. Modifying the following setting will turn off the dialog trail in all softwares using this setting on your system. I made this change several years ago and have had no issues in any typical BIM, CAD, or Microsoft products.
Follow these steps to eliminate the dialog's dragging trail.
- Right-click in a blank area on your desktop.
- Click Properties.
- Click on the Appearance tab of the Display Properties dialog.
- Click on the Effects button.
- Clear the check-box in front of "Show window contents while dragging."
- Click OK.
- Click OK again to exit the Display Properties dialog.