Starting with version 1.0.25 of the Custom Key Mapping tool, you can change the key mappings for all menus to match that of an existing conversation option.  For instance you can have all the key mappings for the selected custom key map follow those of the Optional Conversation 1.  This can be useful if you wish to make only a small change to an existing conversation and don't want to manually remap every option.

 

To do this, select the "Reset Key Mappings" menu option and choose which conversation you wish to use.  The key mappings for the selected conversation will be populated into the currently selected custom key map.  If you are running Unity 4.2(1) or later this can be custom key map 1, 2 or 3.  For earlier versions of Unity there is only one custom key map conversation.  You will be ask to confirm that you want to replace all key mappings with those of the selected conversation before continuing.  You must select the "Save" button before the selection is written through.