How to overcome Error Setting Variable - ‘boot-args’ : (iokit/common) not permitted

According to Apple KB : Prepare your institution for iOS 10 and macOS Sierra

...you must use the nvram command to properly set boot-args NVRAM variable. Starting with macOS Sierra, you must be booted to the recovery partition to run this command.

https://apple.stackexchange.com/questions/256138/trying-to-set-boot-args-with-nvram-gets-general-error-on-sierra

See this answer from @tubedogg. 

It would appear that the change from 10.10 to 10.12 is another step toward including all important security aspects within System Integrity Protection (SIP), meaning that you can't change these things without first explicitly setting privileges. SIP applies to all users on a Mac, including admins and root.

I've just confirmed (because I'm reconfiguring a MacBook Pro with Sierra 10.12.6 just now) that: 

• Disabling SIP using csrutil disable in recovery mode will allow you to set boot-args in a normal boot session. WARNING: You should not disable SIP unless you really need to - and you should already know how and why!

https://apple.stackexchange.com/questions/315120/setting-a-nvram-variable-in-normal-boot-not-permitted-but-allowed-in-recovery-mo?noredirect=1