I haven't seen anybody mention this, but in the second pic down, the cap appears to have a long extension which protrudes down into the steerer and will require locating the expansion plug lower in the steerer. I've only ever seen caps that protrude a very short distance into the steerer. How closely does that cap extension fit into the steerer? Is it conceivable it was intended to help protect the steerer from being crushed by the stem?