If a user builds a link in an ezxml document that uses the node_id or object_id attributes on a link tag instead of a URL, it renders as an A tag with no HREF when using ez_render_field. This is the case with both direct XML entry or when an editor builds an 'eznode://' or 'ezobject://' reference in the EZOE user interface.
There doesn't appear to be any code in place to address the handling of node_id or object_id attributes on link tags in the code used by the xmltext_to_html5 Twig filter. These attributes appear to be passed to the xsl, and I can find no code in place to translate them. I'm guessing this needs another PreConverter similar to how embeds are handled?