If you want to loose weight so badly on the fork ditch the front racks. People used to tour without them, and then all of a sudden they became standard.

The problem with carbon and aluminum forks is that while steel has a distinct endurance limit, Al does not, this is one reason why it is not preferred for forks, where a collapse can be a pretty bad thing. Carbon is a lot more durable that aluminum if properly engineered, but it normally has aluminum parts bonded in. Given they make stuff like aircraft out of aluminum, and climbing gear, I have wondered how big a real world issue this is, or whether it is just a reticence to show up in court with nothing to hang your fork design on. What the science does suggest is that variability in aluminum structures can be hugely contributed to by stress concentrations, and minor dings and nicks, or electrolosis. So if you do want an AL fork, for goodness sakes do not depart on some Quixotic quest to reduce the weight beyond reasonable limits. There is failure out their lurking in wait. A lot of the loads touring bikes are taking are outside the normal range for what the manufacturers a designing for. This is one advantage of MTBs which tend to be ruggedly designed, and a better indication of what is a reasonable weight parameter than road bikes.