Just spent days trying to get a single footnote (essential) to function properly when the manuscript is compiled to the epub3 file format. What happens for the reader is that the link appears properly in the epub output and DOES go to the notes/footnote file. All that is according to epub rules. But the person reading the footnote has no way to return to the place where they started in the manuscript.
In researching this problem, it appears that the “best practices” code of placing a backlink is not implemented in the output of the footnote. So the reader has to return to the table of contents, try to remember where they were when they clicked the footnote, etc. A real mess if there are many footnotes in the epub output.
The solution, proposed initially was to open the epub in a third-party program and fix the problem by inserting the backlink in the footnote code. However, if the manuscript is recompiled, the code must be implemented again in the epub output.
It was suggested that a post-compile python script could be run each time epub is compiled, but this is recompiled. But the solution would be a simple update of the epub compile process. This is in windows version
Please let me know if you are going to address this issue.