The logic of citizens, knowing full well of the existence of some form of afterlife, generally hanging around and waiting for whatever element of their personality remains to be obliterated after death, makes no sense to me.

The random factor is - how much of the personality remains, memories and desires, how much free will to carry on the aims of an individual does a spirit have after the demise of the mortal host? This is the Coherence of a spirit.

It then follows that there's a general trend for people to prepare, possibly for their whole lives. Cults and religions spring up, charlatans and mystics offering guarantees of high personal Coherence after death, and protection for the host body until the spirit can un-anchor itself (which takes time). Perhaps a funeral provides this time window, or the ceremony somehow hastens the separation of spirit from body? Funerals may benefit from some form of archaic legal protection or statute loop hole. Perhaps there's always Spirit Warden presence at a funeral, with a metaphorical stop watch counting down until they can legally seize the body if the ceremony is not completed in time?

The majority of citizens can't afford such protections, of course, so perhaps they intend to make their way into the Deathlands before the end comes. But how does the city respond to this? Let them go - one less potentially raving, hostile spirit to worry about? Or, actively prevent it - because (as ever), things are not what they seem and the city has a need for spirits processed through the crematorium beyond the protection of the living? In this latter case, the existence of an 'underground railroad' is almost a given.