The whole UNIX certified thing is a bit odd to start with, but those addendums are really just saying that because the UNIX compliance tests are thoroughly stuck in the past, a bunch of security measures (that users expect to exist on modern systems) have to be disabled to run the test suite.
SIP is not some irrelevant detail, nor is it an obviously good "modern security practice". A system that the hardware owner cannot modify is not really on the same wavelength as traditional UNIX.