You only need to "update" the NVRAM firmware features (see
Complete your setup). This is for macOS updates and installations. But for that to work, you also need to set SecureBootModel to Default (see
macOS); you have it set to Disabled.
Now if you absolutely wanted to "update" the SMBIOS firmware features, you could (but there's no known reason to), and the value you have there is correct. I've explained this in
another post, commenting on the discrepancy between the NVRAM and SMBIOS values.
To my knowledge, ocvalidate won't check for boot-arg or device property correctness.
For the setup described in post #1, boot-args aren't needed at all. In my opinion, boot-args should be reserved for temporary testing (or for exceptional cases where device properties can't be set).
Yes. Before you can mix and match from various approaches, you really need to be sure of the settings. Otherwise, it's best to stick to one approach.
Good luck!