Except non is not an english word, it is a prefix of latin origin It's a wry verbal shrug. Which is why american style manuals will always ask you to merge it with the subsequent word, without a hyphen
Seven Non-Pornographic Films Featuring Genuine Unsimulated Sex - Pulptastic
Leaving non stranded doesn't work either as it is a bound morpheme, a prefix not a word (in english)
I'd use the two hyphens.
Non tutte le ciambelle riescono col buco (literally not all donuts come out with holes) It usually gets a smile from another italian speaker, because it's a nice way to conclude (even serious) discussions about things that are complex and not working 100% according to plan and for which there may be no solution
