I opened two PRs adding this feature:
Thanks to the research provided by @pjfasano and @lametti, this was straightforward to implement.
With this change, you can place the proof in your biography, your keywords or your social links on orcid.org. Whichever place you choose must be made public, of course. This might be a privacy concern for the biography. In this case, you have to switch to keywords or social links, where you can configure visibility per keyword or link.
If you have questions or comments, please add them to the PRs.