To the Intel folks:
You really need to fix this. Your config scripts presume the key is being input in cleartext, when it's perfectly valid and commonplace to use hex instead.
As best I can tell, the configure_network() function in configure_edison would need to be updated to allow this input, perhaps also along with editing the template in that script used to output wpa_supplicant.conf - it'd need to remove quotes from around the key and prefix it with '0x'.
The wpa_cli tool behaves similarly, and needs a similar fix.
And the corker: it works perfectly, until a reboot. Then, systemctl start wpa_supplicant fails because it doesn't like the key in wpa_supplicant.conf - which has already been proven to work if the checks would stop failing on it.