The provided code has several improvements. First, it replaces an if statement used to distinguish between strings and binary values with a more robust approach using type checking via Python's built-in isinstance() function. This enhances readability and makes the code easier to maintain. Additionally, there are no significant issues or optimizations required; however, ensuring that _v is either a string or bytes is generally good practice for consistent input handling.

If you have specific areas of concern or further details needed on optimizing this particular function, feel free to let me know!