Well, maybe having to continuously rock the trays was AA's way to justify a darkroom assistant! Must be nice.
In the chemistry labs at work they have very mad-scientist looking eccentric platforms that they place petri dishes on to be continuously agitated. I was thinking about making some kind of tray-rocking device for my development trays.

I usually continuously agitate in the developer becaues it gives me something to do, and I think it speeds development, so my prints are probably better-developed for it. I'm not sure if it's the agitation or just the fact that the prints end up better developed. I'm not convinced that agitating film really increases contrast more or it's just because agitation speeds development.