English mostly dropped diacritics since it made things weirdly complicated inter-regionally in England since some regions used them and others didn't. Frankly if you're going to try to reform English through non organic it'd probably be better to just toss the latin alphabet outright and make something new. Personally I'd go with using a derivative of Anglo-Frisian runes personally mostly cause it'd be funny.

Very standard in French? I struggle to remember seeing either.

Nor am I claiming they are. I'm saying it'd make it more interesting.