There does seem to be a method for adjusting headset preload with this thing despite not having a starnut. The Speedlifter clamp has a 36 mm hex nut on the bottom and you use a headset wrench to make the adjustment after the clamp is tightened in place. Look at 1:20 to 1:26 of the video.
That said, this thing is completely unsuited to a carbon steerer and I'd highly recommend against adjusting it while actually riding.