The trouble is there's only 4 or 5 mm of fairly soft basswood under the neck. Recessing a ferrule would take 2 to 3 mm out of that. I wouldn't call relying on 2-3mm of basswood a very secure fitting. Neither does a ferrule spread the load much, which was the whole idea of fitting a wider plate.
Hopefully Alan's luthier will have a go at removing and re-gluing the neck so he doesn't need a plate or screws at all.