Doubt that anyone has done that test. You might contact the Forest Products Laboratories. They have done some testing of the effect of modifications to wood.
But, you could easily do practical test. Anchor on end of a slat and see how far it bends under a particular weight from which it returns to its unweighted position when the weight is removed. Fume the slat and see if there is any change in the bend with the same weight.
Hard to imagine there would be much difference.