Sadly it doesn't fix the bad documentation problem. I often don't care that a field is special and either give a string or number. This is fine.
What is not fine, and which should sentence you to eternal punishment, is to not clearly document it.
Don't you love when you publish a crate, have tested it on thousands of returned objects, only for the first issue be "field is sometimes null/other type?". You really start questioning everything about the API, and sometimes you'd rather parse it as serde::Value and call it a day.