Agreed - This could be streamlined by for example providing a way to set the default options that should be considered when opening a scene with Drag and drop

Currently the options associated with MRML scene are:
Clear existing scene [Default off]
Replace active camera [Default on]

The application settings would provide an entry allowing to either:

• popup the dialog each time a scene is drag and drop
• do not popup the dialog
• change the default option for MRML scene loading

This concept could be extended to all data type and should also apply to files passed through the command line.

Drag and drop of MRML scene has been implemented. Please, create a new issue if there are issue opening MRML scene by DnD.