A lot of IDE configurations, such as VSCode on the default config, highlight Unicode characters that are invisible/look like others (eg. cyrillic characters or non-breaking space) or even all non-ASCII characters, regardless of whether they're in a string or not.

Try pasting any of these into your IDE and see if it catches it. https://gist.github.com/StevenACoffman/a5f6f682d94e38ed80418...

In either case, it would appear as added code, not different characters in the same code, so maybe about the same. If someone changed one character in an existing string though, I think it would be more likely caught visually by someone used to seeing accidental garbage show up