iATKOS | United Kingdom

I've just followed this guide to create the USB: macOS Internet Install

Then followed this guide to downloaded a mostly pre-configured config.plist, then edited the options accordingly as per the guide: Bavarian Cake XPS 9570 GitHub

- I've installed the "Broadcom BCM94352Z DW1560 6XRYC 802.11 AC 867 Mbps Bluetooth 4.0 WIFI WLAN Card," which is said to be compatible OOTB.
- During the installer it is not recognised and I cannot connect to the internet to 'contact the recovery server.' The laptop has no ethernet port.
- Is there a way to setup the config file to force the installer to use the local files on the USB drive? Or is there anything else I can do?