If it is a good idea then Boeing will know about it and incorporate it in the manuals. That they do not take up the vast majority of changes introduced by the airlines shows that the changes are of no benefit. Dumping fuel, as I tried to show, is not a Recall action and there is always plenty of time to do it using the QRH. The level set will always vary, and choosing the max landing weight is only one of the choices. I am still waiting for someone to shoot me down over the possibility of inadvertant loss of fuel on the ground while setting the dump value.