Several publishers (Wiley, Elsevier, Hindawi, more are listed here) allow you to attach your manuscript to your ORCID ID. Like other metadata, this ID is entered in a form at the submission stage, it is not part of the LaTeX code (which in most cases is converted to XML right away). The typical workflow is explained here.
So I would say the answer to your first question is that form-based entry is the accepted way to tell a publisher about your ORCID ID, and the answer to your second question is "no".