No argument from me. I agree that passing a selected list would be a very useful feature.
fyi:
An MTE (Mp3tag Export) file is used by Mp3tag to export tag and file information.
They are text files with an "mte" extension, and can be created in any text editor or by choosing "New" in the "Export"
dialogue.
If you create them outside Mp3tag they should be installed in "%APPDATA%\Mp3tag\export"
https://docs.mp3tag.de/export
/t/1495/1
The trick is to use the "Export" functionality (which creates a text file) to write a script file that is executed when opened by the operating system.
I have some experience with VBS and no knowledge of PHP.
On my system, VBS files are executed when opened. Maybe that is the case for PHP files.
Ask, if you want any help to customize the example VBS script.
Your original post suggests customization will require minor changes.