In that sense indeed

I assume that the destination document is the larger document in which the chapters have been included? What will you see in the individual chapter files if you cross-ref to a different chapter heading in the larger document?

Yes.
The only way you can cross-reference between documents is, in fact, via INCLUDETEXT fields - in this case adding a bookmark reference in addition to the file reference.

To be honest, though, I haven't tried cross-referencing within a destination document between one linked document and other. Whilst I can see how the bookmarking part would work, I don't know whether creating the cross-reference would of itself create the INCLUDETEXT field that would normally be required or whether the destination document can handle that for itself. The worst-case scenario is that you'd have to create an INCLUDETEXT field in the document from which you want to deploy the cross-reference.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

That does sound quite complicated Can't I just put all 'stuff' in one single, large file?

Sure you can, provided the combined file size doesn't exceed 512Mb, but the impression I got from your initial post is that you wanted to maintain the set of seven documents through a single document. Do be aware, too, that whichever way you combine the documents, working with the combined one will be slower than working with the separate ones - even if you had them all open at the same time.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]

Should be oke Running i7 with 16gb of ram here. Combined size is about 200 MB. I did attempt to combine them in a single file, without having the separate documents, but that gave lots of issues with the headings and/or the end lists.

That suggests you haven't used the same Styles, or at least used them consistently, across all the documents. When you combine them, you will have to do that - and some re-formatting/re-application of Styles/re-definition of Styles might be required.

As for the endnotes, all you need to get them to appear at the end of each chapter is to have a Section break between the chapters and to configure the document to insert them at the end of each Section.

__________________
Cheers,
Paul Edstein
[Fmr MS MVP - Word]