Current version does not allow saving multiple documents in one RVF file.
You need to implement it yourself.
Possible solution:
- invent you own file format containing several RVF documents
- save the footer document in the DocProperties property of the main document.
DocProperties is a collection of text strings. Line break characters are allowed, but binary content is not. So you need to exclude rvfoSaveBinary from FootRichViewEdit.RVFOptions. After that, you can save it content to TStringStream and add its string to DocProperties.