Unable to access `vscode:` URIs in `<a>` elements

[srid]

I use this extension to get a preview of Markdown files, via an external process (specifically https://emanote.srid.ca) that generates the HTML and serves a live view of it bound to some port.

When the generated HTML contains the following,

<a "vscode://file/Users/srid/do/index.md">
    Edit me
</a>

.. clicking "Edit me" doesn't do anything. It works on Safari though. It looks like this extension fails to work with "vscode:/" URIs? My goal here is to have that click open the associated file directly in VSCode.

Is there anything I can do, including workarounds, to make this work?

(It would also be nice to "talk" to the extension by asking it to run arbitrary JS or load URLs, but that's probably outside the scope of this issue)