choose between move/copy when drag & drop

maybe i missed it, but is there an easy way to choose between copy and move when using drag & drop, both to the folder tree of FRV and to finder (on mac)?
most practical to me (and also most consistant) would be the same behavior as the respective finder/explorer of the host system, so in the case of mac a simple drag & drop would move, pressing option (⌥) would change that to copy.

is there a way to implement this via the settings? 
and if not, i would love to put this as feature request.
big thanks!