Current builds have options brcmfmac feature_disable=0x82000 this causes errors in the firmware.
[ 323.058492] brcmfmac: brcmf_set_channel: set chanspec 0xd022 fail, reason -52
to fix this, you have to unsquash wireless-6.6.67-pcpCore.tcz and the edit the brcmfmac.conf in /etc/modprobe.d to make it
options brcmfmac feature_disable=0x200000
or it won't work.
Perhaps you need better detection for which model of Raspberry Pi piCorePlayer is running on.
Thanks for a great project.