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Thanks for asking.
Remote Buddy needs to run in the context of a user's session. Since logging out will inevitably terminate Remote Buddy as well, I can't see a way how it could be used to log in another user then - it is no longer running at that time.
Fast User Switching might be something you might want to explore. This could possibly be made working with some UI scripting. Unless of course, security restrictions of OS X prevent you from using UI scripting for this. I really can't tell. I never tried to do this.
Best regards,
Felix Schwarz