They treat the settings as if they don't exist at all, meaning they are incapable of homing. However, a zombie that is already performing homing movement won't stop just because they cross the threshold, they'll go to the end of their current path. If you want them to stop when they get to the threshold, you need to enable the interrupt setting as well.

Ah I see, that's awesome. Thank you. I was kinda afraid of using the Homing feature at all because I thought they would start homing as soon as I got within range. I actually like the idea of a few wandering into my general safe zone every once in a while.