This could work, although we would need a new home for the press room used for live TV games.
Although it's clearly a long shot, I wonder how many seats a 2nd tier to the north or an expanded north lower tier could add?
There is surely some scope as already mentioned in the SE corner. The East Stand Upper could surely wrap around the corners too.
But ultimately we need a proper, fully functional season ticket exchange. The 5-10% of STH's who don't show each game would supply the demand for all but the glamour...