I pushed code for the tweak. The choices are
Code:
'viewer': open the book in the viewer,
'down_arrow': perform a down arrow,
'edit_metadata': open the edit metadata (single) dialog,
'do_nothing': makes the key do nothing.
The default is 'viewer' to be consistent with your change. (
EDIT: NB: I would prefer the default to be 'do_nothing'.)
I tested it on windows 10 in both the grid and list views.