"........... The opening/closing auctions match up all the...

"........... The opening/closing auctions match up all the unders and overs and match them at the price where everything clears.............."

Howdy bagtenner. This is always an interesting discussion and gets more interesting the later the night goes and the more empty the fridge becomes !
Suggest in a perfect world, the way you explained it is the way it would/ should work however do you not agree the potential for games is actually in the methods and timing of placement of the buy and sell orders rather than the method of driving the matched outcomes. Not sure how it could ever be ironed out completely and thus why it remains open to discussion. As a retail punter only hope I, for one, can hang on to is that at least during the day demand on the buy side will outstrip the sell side to the degree the after hours play pretty much falls in line with the daily trend (preferably upwards).
Happy to be educated !