We can all imagine a case where actual running configuration differs from the intent expressed in those settings. I think the OP is looking for a definitive st

We can all imagine a case where actual running configuration differs from the intent expressed in those settings. I think the OP is looking for a definitive statement or disabling mechanism whereby the DHCP client (and subsequently all web browser behaviour) in OSX definitely never honours DHCP option 252, which seems to be the relevant part of the attack described in the article.