Thanks. The second method in the above two posts, i.e. getting the files from the link in reply#25 and copying regulatory.* to /usr/local/lib/firmware before loading r8723bs gets rid of the "cfg80211: failed to load regulatory.db" message. The last few lines of dmesg are now:
...
platform regulatory.0: Direct firmware load for regulatory.db failed with error -2
platform regulatory.0: Falling back to syfs fallback for: regulatory.db
r8723bs: module is from the staging directory, the quality is unknown, you have been warned.
RTL8723BS: module init start
RTL8723BS: rtl8723bs v4.3.5.5_12290.20140916_BTCOEX20140507-4E40
RTL8723BS: rtl8723bs BT-Coex version = BTCOEX20140507-4E40
RTL8723BS: module init ret =0
However, the wifi is still not detected. sudo wifi.sh still says "No wifi devices found!" and iwconfig says "no wireless extensions".
This wifi module has an SDIO interface whereas most have a pci or pci-e interface, including Juanito's "Intel(R) Dual Band Wireless AC 7260".
Could there be something that supports the SDIO interface that we are missing?