由于重复的标头可能会导致各种 Web 服务器和 API 出现问题(无论规范怎么说)，我怀疑是否有任何通用用例可以使用是***实践.当然，这并不是说某个地方的某个人没有这样做.

Since duplicate headers can cause issues with various web-servers and APIs (regardless of what the spec says), I doubt there is any general purpose use case where this is best practice. That's not to say someone somewhere isn't doing it, of course.