Guys, I was just asking what I thought were pertinent questions, wasn't advocating for any outcome. I have sent a couple of people to the Advanced Metadata Variation feature - but I don't know if they made use of it.
If I had a concern it was this: if a separate Advanced FD retained the features of Standard FD, what happens when Standard FD is functionally enhanced. Would users of Advanced FD be clamouring for the inclusion of the new functionality. So if I was to advocate a position, it would be to remove the functionality of Standard FD from the Advanced FD.
FWIW: re Modify EPUB, if Polish Books could remove the cover and non-dc elements, and put the jacket at the back, I wouldn't need Modify EPUB
BR