Official Luthiers Forum!

Judy Threet is another who uses dovetails, and with an interesting twist that only the fingerboard extension is glued. The dovetail itself has a screw through the headblock and into the endgrain to pin it against sliding up and out.

It does save you from having to pull a fret to get it apart, but you still have to unglue the extension to reset it. Bolts are easier because the fingerboard can flex enough to open a gap for flossing without ungluing the extension.

It would be interesting to try combining a bolt-down fingerboard extension with the pinned dovetail. But could potentially become loose with softer rib/binding wood, which can indent where the heel presses against it under string tension. With a full bolt-on you can just snug the bolts down again (and maybe sand the cheeks because the angle's not quite right anymore, and adjust the saddle because the compensation's not quite right anymore...), whereas the dovetail would have to be taken apart and re-fitted.

With a glued extension, the continuous fingerboard grain carries the longitudinal force across the neck joint and transfers it to the soundboard upper bout, so there's not much pressure on the heel cheeks. The neck joint only has to deal with the relatively small torque that tries to pull the lower end of the heel away from the body.