I just bought a custom fixed gear frame that comes with a carbon fork with carbon steerer, off a guy who already cut the steerer lower than the stem so that the cap can sit flush on the stem. Normally I would put a 5mm spacer above the stem, because it seems like the general best practice.
However the fork was already cut so that with the expander in, after tightening the cap, the top of the expander plug would leave 2mm below the stem. I might be able to find a way to shave the top part of the headset a bit to save like 1mm, and since this frame hasn't been ridden, it should settle in just slightly deeper after a few rides.
Either way, should I be worried? or is this normal that it is not a problem?