@ISIWARE No, unfortunately, there is no way to show/hide headers footers upon exporting document to Html Fixed. However, you can decrease spacing between the pages by setting HtmlFixedSaveOptions.PageMargins property:
Document doc = new Document(@"C:\Temp\in.docx");
HtmlFixedSaveOptions opt = new HtmlFixedSaveOptions();
opt.PageMargins = 0;
doc.Save(@"C:\Temp\out.html", opt);
@ISIWARE I have logged a feature request WORDSNET-24543 about this. We will consider adding such option, but currently I cannot provide you any estimates or promises.
@ISIWARE Unfortunately, implementation of this feature has been postponed and is not yet scheduled for development. Please accept our apologies for your inconvenience.
@ISIWARE The issue is not resolved yet. It is still postponed. We will keep you updated and let you know once it is resolved. Please accept our apologies for your inconvenience.