This is easy you need fall off so only the last frets 12-end. Use flat file and go slow marking the tops o the frets from 11-22. Best done with under the string radius sanding tool but a flat file can work. The truss rod does not effect these frets. You want to see metal come off the frets even and slightly more pressure as toward last frets. Make sure you get rid of the 13th high fret that should show on the filings but also use a marker. Recrown the tops and polish it might take awhile but I sure would not pay that kind of money for a plek. Using a full length straight edge after your done should reveal a bit of drop in the fingerboard extension. Not much but just enough to keep action low.
