I’m pretty sure that this chip runs on brcmfmac which is a kernel module. So this seems odd. But it’s a Mac so i don’t know.
Both brcmsmac and brcmfmac drivers require firmware files that need to be separately downloaded. Firmware is available from the Linux firmware repository.
I’m 100% sure it should work with the kernel module. You shouldn’t need the broadcom-wl-dkms installed. But you may have to blacklist some of the other modules. Firmware should already be in linux firmware.