It would be very cool to do a tapered sliding dovetail, but one option
that hasn't been mentioned is cheating by doing a standard sliding
dovetail but with most of the middle of the tail chopped out. This way
it would only bear at the ends. In choosing how much to cut out you'd
have to balance ease of assembly with strength, depending on the
Come to think of it, you don't even have to cut the tail out all of the
way down to the edge of the board, you could leave it just 1/8" or so high.