Viking
fuel in the centre tank WAS used for trim purposes
Don't think so old chap. Centre tank and cofg bear a healthy relationship so the influence on trim by adding fuel to it would be insignificant or very very negligable. In the case of most airliners when empty, ballast is required to improve their handling manners. I think you'll find this is why centre tank fuel was ordered for empty sectors.
As for bollox factor in this thread and the utopian ideals of my mate Nosig (how are you mate?) I note the following:
1) Technical knowledge of things structural ie ZFW and MZFW has led many to utter or pen total bollox. Bollox factor = High
2) The ideals (utopian or otherwise) of qualified or licenced dispatchers most of us share, yet collectively none of us have the balls to take action or do anything about it. My mate Nosig can exclude himself from this criticsm. Bollox factor = low
FEBA