I guess these will no longer be required as the expansion to my local Openreach cabinet I assumed was G.FAST unfortunately looks to be a standard line capacity upgrade.
Setting up a ZISA G1000/G100 for BT G.FAST.
The instructions are very similar to how you configure the unlocked BT VDSL modems. Go to "Advanced Setup, WAN Service". Remove anything already there and Add a new entry as follows:
WAN service type: Bridging
Service description: br_0_1_1.101
802.1P Priority: 0
802.1Q VLAN ID: 101
VLAN TPID: Don't select anything
Go through the other settings and get rid of anything not needed:
Quality of Service: Disable (if managed by your router)
In "Management, Access Control, Passwords", change your "admin" password. This is also used by Telnet and SSH services.
In "Management, Access Control, Services Control" untick EVERYTHING in the WAN column and then Save. This is very important otherwise you will be exposing telnet and the other services to the Internet. You should also untick anything from the LAN column you don't need (except for HTTP, which you need to manage it).
Finally, you need to configure your router. Set the connection type to PPPoE with a username of "firstname.lastname@example.org" and password "password".