now this design exists in an instrument, in one form. I can't show it because the designer hasn't gotten back to me. I always thought it made sense,if it was done right. I had a chat with a few buddies brainstorming the concept and if you had the ability to remove the fretboard from the neck i.e make it detachable, it could be done.
let's start with the cross section of a traditional fret
has the tang that holds the fret in place
what I want is to incorporate the frets and the fretboard. make it out of aluminum or stainless steel
with cnc machines and the best quality materials you could make an accurate and durable fretboard.
and then scalloped frets. would be easy
treat the fretboard with anodizing and you will have something that is going to last a long time
no fret dressing and no frets falling out.