Even better: Add fn term%{ $* } to your profile and you can just dbl-left-click and send the old command. And since Rio remembers your last menu item selection this becomes just dbl-left-sgl-middle-click on second execution.

Pretty neat.

Edit: Of course this does not make it much easier if you really just want to execute the very last command. But usually you want to either

* edit the last command, because you mistyped it, in which case you can edit the old command in place and then proceed as described above

or

* you want to execute not the last but some previous command in which case this becomes increasingly useful the older the command is