That's a shame, it would be a really useful feature. I want to host my own server (locally, on my vdsl broadband), but don't like the idea of my remote connection being totally dependant on it. If I'm in the office near the RU server, then obviously rebooting it isn't an issue, and if my broadband is down, then it doesn't matter that the server isn't online anyway.
But I need to be able to dial into my hosts from anywhere - when out on the road working, if I go away for the weekend, from my laptop or my phone. If I'm away and my private server is offline, there's nothing I can do to get it going again.
So I can't do unattended access in that situation, which is a bit of a pain. But worse than that - I can't even ask the user to start Agent and initiate a connection using the public server - because the RU host service is already running in the background and the user can't stop it. So in that respect Host and Agent are not mutually exclusive - they can't coexist together.
Using another remote desktop software as a backup is a hassle - means I've got to double up all the configuration, installation, and management of two separate systems. I'm actually trying to get away from another product (vnc), and I like the aspect of not having to setup port forwarding for hosts (mainly because it gets broken every time someone resets or replaces their router).