@stefanadelbert Is Docker an option for you? I often run Caddy and zrok in Docker because it simplifies saving and remembering the various interdependent infrastructure and application configs as a handful of files in a single folder with Docker Compose.
That's the only way I can think of to do it with the zrok share examples we've published so far. Frontdoor was conceived for always-on public shares, and I can see the utility of a private share Linux service, too.
This example could be adapted for private shares or accesses or both. It uses a systemd feature to parameterize the service unit as a template for many service instances.