Option to add both lowercase and uppercase ID3 tags for portability

[grr]

Since there are many software/devices that still only work with uppercase or lowercase tags, can you add an option to add both uppercase and lowercase tags?

Edit: I saw the large section in the README about tag casing, but the conclusion to just report to each and every implementor is not practical at this point. Hardware vendors almost never respond in a timely manner, if at all. Many of us have multiple devices and software programs, so at the very least, maybe include an example on how to add the additional tags using an external tool.