You wish you could turn (e.g.) a solid door into a french door while maintaining the other settings (trim etc.). Well wish for something else!
Select an object and open the settings. Navigate to the object you want. Hold down Command and Option and click on the new object. Any parameters the two objects have in common will hold their values. Parameters in the new object that aren't in the old one will keep their default values.
In our door example, all of the settings related to trim, materials, open angles, etc. will be saved. The divisions of the french door will be the default divisions.
Very exciting.