Many CoffeeScript constructs were adopted into JavaScript and TypeScript, but unfortunately, heregexes weren't among them.
Later languages have added support for the `x` flag, including C# and Rust. There is also a stage 1 proposal for JavaScript: https://github.com/tc39/proposal-regexp-x-mode
I probably use regexes the most in notepad++
Many CoffeeScript constructs were adopted into JavaScript and TypeScript, but unfortunately, heregexes weren't among them.