Thats my view on it...I can't see a center lift hurting it, only helping it. Makes me a little more warm and fuzzy knowing its on 3.I'm not sure. That was what was relayed to me from Bennington. I think I've seen other threads discussing this and if I remember it has something to do with carpet over pressure treated wood. The carpet stays wet and the pressure treated messes with the aluminum.
My QX is much heavier than your 22 but if I had a 22 and was building a lift I would have done the center bunk also. I always like to over build.
Your lift looks great.
Your boat looks insanely nice by the way...do you have posted photos of it on the forum?
edit...found the photos...yup, beautiful....