Oh, this is a proposal. Just had my coffee..
Downsides? Round robin. Handicap.
Just can't see something like this ever occuring and it fails the KISS test. Trouble is if you devise a mousetrap that is too difficult to use or comprehend nobody uses it or buys it. Hockey particularly has the problem of being a sport that for non fans is a bit difficult to catch onto. Adding any complications, levels of rules, just causes casual viewers to turn it off or stay away. Try explaining in a telecast to a new viewer in Texas that Team A, even if they win the game, they lose. Unless say they win by 3 goals or some nonsense like that.
I understand the rationale of creating a handicap or hedge. This works in betting. Generally it isn't what attracts people though to actually viewing pro sports or competition. On the ice it should be the winners winning, in any format. Not some team backing in because they got a sweet margin to work with.