You did not answer what VPN tech you are using.

Without that knowledge i would recommend setting up tailscale and having your users use that. If you want to be fully self hosted you can also run Headscale as the control plane instead of relying on Tailscales own service.

I recommend tailscale as it is very easy to grant a user privileges to ONLY use an endpoint as an exit node but also grant access to any other endpoints as needed (such as your future jellyfin server) via theor ACLs.