Box set
There is no chance whatsoever of box set being replaced by the more correct form boxed set. So stop seething about it and causing yourself distress. The form, boxed set has been in use for 125 years or so, but the Oxford English Dictionary has dug up a reference from Wisconsin in 1969 to a ‘box set of tumblers’. Admittedly, binge-watching a set of tumblers for hours on end would be a minority interest. The triumph of box set is partly a matter of phonetics. In ordinary speech the d after the s sound in boxed set is hardly out before the poor old tongue gets round to hissing the initial letter of set. There is an analogy here with sixth. I have heard people complain of news-readers or actors on television mispronouncing sixth. The tendency is to say sicth.