Here's a theory from my stoned ass: it's better to do it early, i.e. in veg, because the plant wouldn't have spent the energy on those nodes vs if you were to wait for flowers to start to chop. I just get nervous cutting off all those nodes in veg because some of them randomly end up being a fat ass nug even tho it's in larf zone
The way yall trim, removing fans, reduces the amount of energy the plant takes in. All energy comes from light...fans are most efficient at capturing that energu and converting it to c6h12o6
I have yet to find a strain that doesn't do better with intense defoliation - no matter if its early veg, late veg, or early flower. To be on the safe side though, I do it in 2-3 stages throughout veg and the first two weeks of flower, just to be sure no shock occurs.
The way yall trim, removing fans, reduces the amount of energy the plant takes in. All energy comes from light...fans are most efficient at capturing that energu and converting it to c6h12o6