Hi melville74,
My apologies for the late reply!
“If I need to change a passphrase on an existing GX450 would I just apply the template to the unit in question?”
Yes, you can do this in the Monitor > Systems tab. Just click the box beside each device you want to change the WPA2 password on and then click the blue Upload Template button:
“Is there a way where I can view an existing WPA2 passphrase on a unit?”
You can also view and change the WPA2 password on a specific device by clicking on the device and drilling down to Configuration > Wi-Fi > Access Point > SSID > WPA/WPA2 Personal:
There is an ‘eye’ which you can click to reveal the current password.
Regards,
Nick