I'm for defoliation for my benefits but I don't subscribe to removing leafs improving yeilds or benefits the plant.
I've seen myself dense nuggets top to bottom without defoliation.
View attachment 5365796
Grown all its life under a leaf
View attachment 5365798
View attachment 5365797
I've lots of examples, buds are a product of the leafs imo.
If we take the light gathering off the table, we're still left with leafs transpiring and drawing in nutrient, the leafs are still exchanging Co2 and oxygen, they're storing excess srarch which gets used during the dark period, this is easily verifiable with a iodine stain test.
Imo even if the lower leafs aren't catching more than 400umol it's no reason to remove them, they bring to much to the table.
Fwiw I use defoliation to slow down my mother's in veg and to slow down growth after flipping, without leafs there's not much growing goes on.