a few people have compared the differences in fruiting between dunking
and rolling the cakes in vermiculite versus crumbling the cakes and
casing them and have found that there is very little if any extra
yeild to be gained by crumbling and casing. Also by crumbling the cakes you:
a) risk more contams b)
take longer to get fruits because the mycelium has to repair the damage
made by crumbling (if you dunk and roll your cakes, they can start
fruiting immediately) c) your mycelium wastes nutrients it could use to fruit because it has to use them to repair that damage.
Because a casing layer is non nutritious, the nutrient content is the same in the crumbled cakes than in the whole cake. The reason why we case, which is to provide the mycelium with a reservoir of water, is more than adequately covered by dunking and rolling
the other hand, crumbling to poo, enriched coir or another bulk
substrate adds loads of new nutrients, and once the mycelium has
colonized all that substrate it can make lots more fruits.
in conclusion, if you want the fruits as soon as possible, just dunk
and roll and put the cakes in the fruiting chamber. If on the other
hand you want a bigger yeild and feel confident that you can make bulk
substrate without introducing contams, you could crumble the cakes to
a bulk substrate, then case the bulk substrate (or not) and fruit.