Issue Resolved
Upon further searching on the forums, I found this configurations which works. Configure the RG1xx as described there.
To answer my own questions:
1. Clearly I need to enter something for the “CUPS Boot Server”. Anyone know what the URL is and what certificates I need?
Nothing needs to be entered for the CUPS Boot Server. The LNS certificates and URL need to be added instead. See the other forum post for more info.
2. Should I be using au1 for the CUPS server or should I be using eu1?
Use au1 for both the CUPS and LNS server.
3. Do I need a client certificate under the “CUPS Certificates” and “CUPS-Boot Certificates”?
No you don’t.