Guitar fretboard blanks

OK just out of curiosity, a friend of mine mentioned about kanberi.

After a few times, it won’t be levelled. So instead of making a Sao from scratch with Two blocks of different wood stuck together, would something like a blank fretboard do well on a Sao?

Just like the the eclipse which is topped with shitan all the way to the tenjin.

That’s essentially what happens, yes.

This video has audio from a 141 year old shamisen (!!) that was restored by replacing the fingerboard with fresh wood.