I think never mind should be one word.

I’ve been reading a lot of old (1920-1940s) newspapers this year and it amazes me how much words, usage and spelling change. For example, in the 1940s the Washington Post used the word “indorse” instead of “endorse.” Candidates received “indorsements” etc.

So, I think there’s room for growth with “never mind.” If nonetheless can be one word and insofar (but not “insofaras” — even though nobody uses insofar without the “as”) why can’t never mind be economised to nevermind.

On the wisdom of this insight, there can be no debate.