You can edit and export, is that correct? I don't think we're going to be adding an editor in the UI at the moment.
Yes, currently your only option is to edit the files outside of the UI. If we still won't add an editor in OSP14 - let's move this bug to 15.
I'd prefer to have a new RFE for "directly edit plans in the UI". I'll make that for 15 as a clone of this and close this one.