"-": this is a control within character sets. Escaping content for use within character sets is already fully supported except for this character, including escaping "]", which doesn't need escaping except within character sets.

"}": this isn't a control anywhere except within quantifiers. Within a quantifier, escaping this results in an invalid regex. escape-string-regexp doesn't, and can't possibly, support escaping strings meant for a quantifier context.

If you approve of the change, I'll make a PR.