Feb 07 2017 01:26 AM
See this about how global navigation works now http://sharepoint.stackexchange.com/questions/206724/how-to-add-node-to-structural-navigation-csom/2... - pretty bad as fake urls etc. are needed
Headings are not implemented at all http://sharepoint.stackexchange.com/questions/113712/creating-a-navigationnode-of-type-link-from-cso...