Re: Compensated locking nut?
Looks like it "lipped-over" the edge of the board,,,,,,,but that creates a problem. (probably why it never caught-on) Height-adjustment
If you had the exact fret-height it was designed for then it could work fine, but if your frets were shorter then you'd have to endure extra clearance over the first fret. Or you'd just have to shave-down both the slot and the edge of the board,,,which would be a pain for most people.
If you had taller frets and then shimmed-up the nut then there would be a gap under the nut's lip, like between the board and lip.
Now that maybe wouldn't be an issue but it would create a fulcrum effect (if the gap wasn't filled with another shim of some sort)and then that could contribute to the nut's mounting screws eventually developing wiggle, which would eventually get worse over time.
Also, just by looking it appears that the Earvana and EB have slightly different "optimum" compensations,,,,,,,which only makes sense if they're optimized for different gauges/tunings/tensions. ????
I'm betting they realized this after devoting much work lol, then realized it wasn't likely to catch-on because of that,,,,,and because the metal crowd is so varied now on their choices of tunings/gauges/tensions.
I realize that you could still adjust the saddles,,,,,,,,,, but optimum is optimum and not-optimum is not optimum lol.
So maybe it somewhat defeats the purpose when all is said and done.
Anyways, they probably "optimized" them for E-standard with 9-42,,,,which most metal guys don't even use anymore.