Full instructions on how to set up an 'Open Tab Rightmost' plug-in within Sublime can now be found here:
Brilliant, thank-you for that!
Thank-you FichteFoll, however it would appear that doesn't solve my problem as the new tab still appears to the immediate right of the currently focused tab. I guess this is due to the tab (view) not having being attached to a window at the point at which the event fires.
Customer support service by UserEcho