Gotta disagree here. In my case, the one receiving the most direct and intense light, has the biggest leaves; easily twice as big as the rest. The Cree cxa3070 does not lack light in the ranges you mentioned; in fact, it focuses/specializes in those very ranges. It spikes in both, but is red-heavy, with still plenty of blue, and minimal green. The spectral curve graph of that particular cob has been posted here and elsewhere, many times.
I have... a few, beneath a pair of 3070s, and the 3070s are adjacent to each other, which creates a super-intense PAR overlap region in the center, where the center plant has enormous primary (and secondary) fan leaves, while every other one's fan leaves are literally half the size or less. I actually bleached them a bit early on, because those crees are pretty intense, and i had them a little too close (but the node spacing was awesome, pre-stretch, and before i had to back the lamp away to let them recover...). Those biggest leaves are also the darkest and most opaque. My hypothesis is that the plant "senses" that there is SO MUCH useful light, that it "knows" it doesn't need to go "up," but needs to grow the leaves as big/wide as possible, to harness all of it, because it Doesn't have to "reach" for anything; everything it needs is right there in its face; it merely has to grow straight out and up, and more leaf surface = more photosynthesis ("senses" may be the wrong term; it's likely more accurate to say that it simply grows the most where it touches the most and best light... due to an abundance, which accelerates growth... and since it's getting plenty of intensity, it favors horizontal growth instead of vertical growth). The others stretch more and exhibit "reaching" characteristics, whereas the one in the center simply "gets huge." It's also got the thickest stalk (6wks above ground, 2wks into bloom, stalk thick like a thumb, trying to grow roots out of its neck, despite being buried deeper than the others at transplant). Prior to flip, it was the shortest, bushiest, widest, and was the first to pop. It stretched a bit and caught up, then vertically surpassed all but one, and i had to tie it down to prevent it from "stealing" light from the others. It was hogging the PAR overlap cone and depriving the others of direct light. On each side of that one, one is stretching like crazy, while the other seems to have stretched very little, if at all (which means it's now receiving mostly obstructed "filtered" light; i think i'm stuck with this issue, because i don't want to do anything drastic and stress them at this point), but has the prettiest leaves (this is the one that has been the prettiest from the beginning, which i suspected might turn out male, but didn't). However: the cxa3070 "lacks green" (not completely, but relatively speaking), so when blue and red are filtered by upper leaves, there isn't much green left to reflect or penetrate opaque leaves. Ideally, i'd should use 2 more of these same cobs, but it's not necessary. I just have more canopy than PAR cone, partly due to configuration. Everything in that PAR overlap zone is thriving; everything else is "just okay." I don't have dying leaves everywhere; just a few, at the bottom, because the canopy has already claimed the majority of useful light. My lowest massive fan leaves will probably go soon... because they don't get much light anymore, due to the massive fan leaves above them, as well as all the other flower sites occupying all available PAR cone space.
TL;DR:
cxa3070 delivers primarily red and blue, and of mine, the one directly beneath the lamp, receiving the highest amount of intensity, has enormous leaves, while the others are at best half the size, despite the fact they clearly receive less of the exact same spectrum and intensity. Everything in my "hot spot" gets huge and dark; everything else is smaller, brighter, thinner, less opaque. Top leaves tend to be darkest and most opaque (after sufficiently maturing, of course).
If the "not enough red/blue" assertion were correct, the lowest leaves, and those on the edges, would be the biggest; not the ones directly in the center of the highest intensity zone.