Here is an interesting discussion on the topic of this thread embed-non-pdf-files-e-g-bibtex-into-pdf-with-hyperlink-in-the-pdf<https://tex.stackexchange.com/questions/418606/embed-non-pdf-files-e-g-bibtex-into-pdf-with-hyperlink-in-the-pdf>
The post lists 9 criteria for a useful embedded file that I mostly agree with. Then LateX packages are evaluated against the criteria by testing with several pdf readers as I did with Joel's pdf file. The packages are: embedfile, navigator, attachfile, and some combinations. None satisfied all the critera and this lead to writing a new package, intopdf. Unfortunately the new package was not tested. I am still interested in how to get any of these working with Lyx.
