I think it is worthwhile showing the continued life of these kit guitars. I keep learning from and messing with it in ways I would never on my production guitars.
From the get go the plastic nut on this was a problem that needed attention. Way too high affecting playability and the intonation on open chords. Also the string routes were cut way too deep and the wound strings caught up and it caused tuning problems.
So I finally bought a bone nut that was all pre cut and ready to drop in. All it need was some reduction in the overall height. The original plastic unit knocked out easily enough. I cleaned out the recess and put in the bone nut. Comparing the string height to first fret on my nice playing ES335, I needed to remove 1.25mm on the wound side and 1mm on the other. Using a few grades of sandpaper I reduced the height, re-installing and checking along the way. Once installed, it completely improved the play-ability of the guitar. Open chords now easy and spot on with good intonation. The lower nut height also reduced the action down the fretboard improving play-ability.
Overall a very cheap upgrade that has had a huge positive effect on the guitar. Highly recommended, if not mandatory!