SUGGESTION: Make possible to use FILENAME as a "tag' field in the Tag Panel

This comes out from me pointing out the obvious aspect in this discussion:

I see no reason whey the users should be allowed to edit _FILENAME in the Tag Panel. _FILENAME_EXT- now that would be a different story, because changing file formats in Mp3tag would mess up the usage of the files. But a mere _FILENAME? All bad that can happen is this: the user gets the pop up windows informing that for example

File "C:\Music\Hans Zimmer\Inception Opening Titles.mp3" cannot be renamed to ``File "C:\Music\Hans Zimmer\Opening Titles.mp3".
Cannot create a file when that file already exists.

And such pop ups are already appearing- the mechanism for them is already built in Mp3tag

the plain fact is: _FILENAME is no tag field but a file property.
an underlying systematic is: none of the information fields starting with an underscore can be modified/added in/to the tag panel.
And no, I don't have the same filename in different folders as there are numerous devices out there that do not support folder structures to create unique filenames so they have to be unique without being a fully qualified filename.