First - nice job with cnix! 
I installed it on an old macbook air this morning, the wireless networking hardware wasn’t recognized - which isn’t surprising in the least. 
I downloaded “broadcom-sta-dkms_6.30.223.271-23_all.deb” for Debian 12 from http://ftp.de.debian.org/debian/pool/non-free/b/broadcom-sta/broadcom-sta-dkms_6.30.223.271-23_all.deb on another machine, installed it & rebooted. The download, install & reboot took less than 10 minutes and I’m typing this on the macbook air. Thanks for including dkms - being that I’m not a Debian user per se, not sure if it’s included in the general distro.