Send them a painting of alexander

Totally a viable alternative.

Or ! Or or... or you can just make your characters go through the bad stuff one by one without having to let them stand their ground for no reason.
Or just play undead characters, because fuck poisons.
You seem to be missing the point. That being, I WANT them to stand in the hazardous area. It's not an issue of trying to path them through. It's that i want to know if the functionality exists to make them stay put without being under player control regardless of what their situation is. I take it though that such functionality doesn't exist.
As for undead, they play well with poison and death fog of course but not other hazards so...
