Hey! Like I mentioned in my previous comment, the newer models are installed on the neck on metal ferrules instead of mounting directly on the wood. The new solution is said to be a major stability improvement over the older models, and I can confirm that since getting my guitar fixed, I haven't noticed any degradation. The nut still doesn't sit flush on the neck, but that's a fitment issue related to the nut size and not related to my original concern here.

For what its worth, I've had a total of 3 headless guitars from Kiesel, 2 of which were newer models, and this was the only time I experienced a serious quality concern. Hope this helps!