Thanks @Moe , that's really interestingI’ve made the David Heath Verdant IPA twice, the first time dry hopping at yeast pitch and the second after fermentation. I also did the same with Vacant gesture ( a dry hopped blonde beer)
Both beers had much more hop aroma when dry hopped after fermentation had finished.
Originally I was dry hopping "normally" at the end of fermentation, generally with good results.
I wanted to experiment with dry hopping early for a couple of reasons - biotransformation of hop compounds when the yeast is active, and limiting O2 exposure.
But at least one of those reasons has gone away so next time I'm gonna go back to dry hopping at the end (possibly try again with cold & short dry hopping)