At this moment on my MacMini with Broadcom B4306 chip I am working with mossys:net directory from 3.8 except B43 file that I got from 3.7 and I solved all issues I had updating to 3.8

(i.e. I experienced MorphOS boot log stating that a device was not found [Wlan], the same wlan Wifi appearing randomly at reboots, connecting with Ethernet cable not working anymore anytime I tried to save WIFI preferences when WLan0 device was present in the device list, and Preferences/Network that hanged up at random moments)