I don't have hard data (which is hard to do for this) but anecdotally speaking, the whole plants SEEMS to benefit some if most of the plant is getting UV, so the lower and mids get some bump, but not nearly as much as the buds that are getting direct UV. It's one of those things we get conflicting feedback on, although most say it helps. It may very well be strain specific, or a false reading due to a lack of hard data. My guts says it probably helps some at least with some strain.I'm trying!
I can tell you even the plants under UV are showing signs of distress in the leaves, but the buds are still A1 quality. But I think that is more about the strain than the grower in this case.
Also, it seems that our original hypothesis that the UVR8 response is local to the area hit by UV seems to be holding up. I think that a dense canopy under UV will show results only in the areas directly in the path of UV, lower buds will probably not be effected. This might require a staged harvest where the tops are taken and lower buds are then allowed to further ripen now that they are getting UV. Dunno, it's still early.