My Zero Fret and wooden Nut/Retainer arrangement is about getting the advantages of a Zero Fret setup without the downsides, as well as removing the need for and problems associated with an angled back or thinned headstock.
The design is highly refined in every way, it allows me to get proper lateral hold AND set the pressure on the zero fret to a minimum (avoiding the usual problem of wear on the small contact point) AND maintain the tension and pressure needed for tone (moved from the Zero fret to the wooden nut and retainer surfaces- tonewood that is directly, high pressure glued to the neck).
A Zero Fret can have the hard, polished and minimal area contact point that is the ideal. Usually though, the downforce that is required for good tone will cause the string to quickly wear away a small contact point, even on the very hard stainless steel fretwire that I use. This will ruin the quality of the contact point surface and move the intonation point slightly. The nut arrangement therefore holds the string so that the downforce on the Zero fret is minimal- just enough for a clear sound, and no more, both to avoid wear and to avoid changing the intonation of the heard note. The nut also holds the string against any sideways movement over the Zero fret that would cause wear.
This arrangement also moves the position of the main transfer of the force of string tension from the intonation point to the surfaces of the wooden nut and retainer. This protects the contact point, but also means that energy here is travelling through wood that is directly coupled by a high pressure glue joint between highly refined surfaces- a principal of the Naiad design in many ways, and the same as on the Bridge arrangement. Another advantage, which is again also present on the bridge arrangement, is that bending forces from string tension are distributed both up and down, which acts to balance the forces felt by the neck, reducing the need for truss rod counter forces and the inherent distortions that these bring.