Quite a few things can't be disabled; for example AFAIK it doesn't offer a way to disable the autocomplete altogether, or the "fuzzy" matching. I really dislike these things. Fish is a great shell, but very opinionated which is great if your preferences align with that, and not-so-great if they don't. Which is fine because it makes the project better for those who do want these things, and not every project needs to cater to everyone.