monocoque stucture needs little reinforcement for alot of strenght, add more layers of glass and you get very little actual structural gain with more weight.
the issue with the large phantom is lots of surface area to cover, an small increase of a laminate = a large increase in weight!
but saying this i bet a bit more weight wouldnt hurt for the small boards, but dont complain if a boards breaks after a smash against a rock or sailed over sunken refridgerators !
the phantom however is an all out raceboard , get the phantom 320 instead if you are worried about dings. my friend has a mistral equipe and a mistral superlight 2, the superlight two is fragile , way more then the equipe same shape but a wee bit less weight.
sailors it your choice!