I spin for myself so it doesn't matter to me. When its real hot in summer I often cut every buns wool off. I may loose some for spinning because I timed it real bad but the comfort of the rabbits matters most to me. When I do hit it good enough for spinning, I can spin it as long as its at least 2 inches in length. Plucked or cut i have no probs spinning.
My English and crosses that are more English get cut more often just because they matt faster than the rest. I spin that to as long as its not a matted piece.
I dont sell fiber but if i did I would only sell plucked to get top dollar. I think that is where it matters most, value for selling.