Just set the name of this mob to either DLNF or SVASUDNF and place behind the closed PK gate to jump players to NF.DL >> NF
SF >> NF
Also is a hack to Door Manager to make the switches do nothing in these 2 PK's.
This can also be done by changing the door position to more than 200 units from the switch but will give the player a message about not being close enough to the door or some sort. I am sure @PlanarChaosRvrtwo can confirm this method.
Hope it helps.