Okay I've given a general search and can't find anything online about this, so what is the general opinion on weighting boards to get more flex from them. Personally I do it and find it to be no big deal but other people say that it kills your board. When I do it I am sure to do it with the bindings off and make it a 6 day process, that is with one day of weights (about 100 lbs) over the middle on the top and one day on the base (I put a plastic bag under the weights to avoid them making direct contact) then the same above and below the binding areas for the other four days. This is all with the nose and tail of the board resting on two chairs. It seems to have helped break in my board and given it much more flex.
Wouldn't it be easier to just get the board with the flex you want to begin with?