Thanks for the response. My understanding is Remote Streaming is using a DDNS basically with a Channels-supplied custom domain (plus some token-based OAuth). There must be very little effort to publish a static user-supplied custom DNS name in place of that Channels external service-side dynamic host instead, no? It would literally be one more text field config in the Channels DVR Server config that would just override your custom server-side logic.
Edit: This would essentially be a “Custom DDNS for Remote Streaming” field. Simpler than Tailscale support surely