I'm running into the same problem too. I followed the instructions from the blog, nothing seems to work. The wpa.supplicant.conf file can't be edited or overwritten. Node red fails to start among other things upon initial install. Under rasppi config the supplicant file is not found.
The old firmware installed just fine, so I know the rapberry pi functions. But I'm upgrading to the new arducam 16mpx camera, so the old firmware won't work.
Any help or answers on this would be great. Thanks!