misting actually does several things that make people believe it is more necessary then it is.
it incidentally exposes the grow to light. Evaporation brings the temperature down. Co2 is displaced.
but don't worry about all that. A light misting or two will help if your chamber is not properly humidified, it will keep your casing wet, hopefully to field capacity.
remember that evaporation will occur even in 100 percent humidity.
now, if you are not casing and your substrate is overlayed, misting will not do you much good. The mycelium will not directly absorb surface water.
so in that case your misting only serves to wet the walls of your chamber for a while.
if you are casing, you are best served misting gradually heavier after your first flush in anticipation of bringing your now moisture depleated casing back to field capacity just before your second set of pins. Same holds true for flush three. If you do not intend to immediately turn around and grow more then you can continue with further flushes. If you value your growing environment then you are done after 2 or at mist 3.