grity,
there is a graphic for whigt and balance (CG limits) on s.10
the range for an A330-200 with 210t is from 17 to 39%
there is no advice that the stability is badly different in this range...
and no advise what is the most stable position of CG (24...26% ???)
Interestingly, I noticed the same thing you did and ask the same question to myself. If I interpret the A-300-200 for a 205 ton weight, they were operating within the limits, but right at the edge. For the -200 the limit is just under 38% and they were at somewhere between 37.3-37.8%. I would have to believe one would have better control (absent the computers) if the CG was as you suggested. The capability is there to pump the fuel either way, from or to the trim tanks. I am not sure how long it would take to pump the quantity of fuel to the center tank from the trim tank to equal a 24-26% CG.
Tubby gave an estimate of the amount of fuel in the trim tank in
his post #1253. However, that said, it could be pumped back to the trim tank after the perceived turbulent episode was over to regain the desired efficiency. Perhaps one or more of the A-300 pilots could comment on the pros and cons of this idea.