What are the triggers that update the map?

From my first playthrough it seemed that doing certain things updated the entire map. Enemies start spawning, some enemies despawn, regional effects are applied or removed, etc.

Is there a comprehensive list of these triggers and their effects? I can't seem to find any, yet they're infrequently mentioned by the community.

Do they correlate exclusively to labs? Which part of the lab, specifically? Picking up a Burgl chip? Upon first entry? What should be avoided if a player wants to remain in an earlier stage of the map?

For example, the haze emitter. Do infected enemies start spawning once the haze emitter is plugged? Or is it upon entering/completing the haze lab?

A comprehensive outline of these stages would be useful.