I have worked with some of these architects on similar houses in the past. At some point the client realizes they are paying for bespoke work and they want to see the craft. Other times the architects will present them to their clients like this as a form of frameable art at the very end.
It’s literally no different for them than going down the street to purchase a hand-woven sweater, a hand-dipped candle, or home-made brownie: They are paying extra for the human touch and want to see it.
CAD is the way drawings are done for people who are building and coordinating. Hand drafting is still done for presentational purposes. It’s probably partially design-build anyway, so you are expecting the trusted contractor to pick up some of the details as well.
