Interesting, this is an idea I had a while back. But I wasn't convinced it would be any lighter than a steel normal 1.1/8" steerer. Out of interest, when you get time, could you tell me the internal diameter at the bottom of the steerer please. A quick calculation (after accounting for the thread depth) makes the wall thickness 2.55mm, which is thicker than some Pace steerers. I wouldn't like to tighten a locknut particulary tight though. Possibly fine with something like a headlock!
Internal diameter at the bottom is exactly 22.0mm (I expected 22.2, but nope, micrometer said no!) honestly, I can't see the benefit, the threads and groove are not the best, and the alloy is soft.
I have a set of AMP forks with an alloy steerer, and the alloy on these is WAY thick, 4mm+, I had a set of pace with alloy steerer at what must have been less than 2mm, so any internal diameter would have to be fork specific.