Yes, I do remember Boro taking Chelsea's place in the old First Division and it all kicking off at the Bridge following the 2nd leg, leading to the EFL binning it off.
But this was back in the 80s. Football was a very different animal back then, with Chelsea being one of the main protagonists...
All Stars north v south utterly pointless. They do it in baseball (American League vs National League) but its just a meaningless exhibition game. Why add that to an already congested calendar ?
However. I've long been a fan of the concept of a relegation playoff. Bottom 2 go down, 18th place...