It ought to be possible, but it's not as far as I know.

You could use ALT+Insert, but then you'd have to decompose. On the other hand, if you're on a PC, the right-click context menu is faster and simpler than the CTRL+C, CTRL+V method...

Command-D would be nice but I would rather have them fix bugs than add that.

You should be able to assign a keyboard shortcut to the Duplicate command, inside of the Customize dialog. Command/Control-D is set to Deselect by default, but that can be changed or deleted. You can also adjust the Duplicate offset (how far from the original the copy appears) in the Preferences under Glyph Window > Dimensions.

Great and thanks to all of you for your tips. I'm on MAC, I had not thought the Duplicate command. By default my Deselect command is Cmd-U so Cmd-D to duplicate will works perfectly to me.

Just checked and Cmd-D is already assigned to Duplicate on my set up. Forgot about that one. Thanks for the reminder.

Now if only Adobe would make that consistent in their suite!