I am set now, but beta readers tell me that the backlink of the footnote works only so-so.
Do you have this experience, that going TO the FN works fine, but going BACK to the text does not work as well?
What does "so-so" mean? If the links/anchors are created correctly they will work (to or from). If the're not created correctly, they won't work. There should be no in-between.