Agreed. That’s best. You want to avoid port forwarding on the BT Hub if you can and never ever forward port 80.
A router has a firewall and controls traffic between its WAN side and its LAN side. Port forwarding punches a defined hole in the firewall, so forwarding port 80 on the BT Hub would have allowed a device in the interwebs hitting your port 80 (which probably happens hundreds of times an hour) to be forwarded to something on your LAN. But your Beryl isn’t presenting its web interface to its WAN side (the Hub’s LAN side)