You'll have to bring this up with AA, since I've never used it. See page 229-230 in "The Negative".
Haven't used what - sheet film? Or agitation with sheet film?
I have a fairly modern edition of the book (19th paperback printing, 2015). On page 209 in the introductory paragraph on tray development of sheet film it says:
Agitation is more complex than with tank development, and careful attention must be paid to the frequency and timing.
He then proceeds to explain an agitation routine that cycles through a stack of sheets every 30 seconds and points out that the 30-second cycle needs to be adhered to regardless of the number of sheets, so the agitation routine needs to be adjusted for the number of sheets so that the cycle time remains a constant 30 seconds. The agitation routine he describes furthermore involves constant manipulation of the sheets, to the developer in the tray will be in constant motion.
I frankly didn't remember the 30 second thing by Adams, although as pointed out earlier, I do use a 30 second cycle myself as well. IIRC I based this on the regular Kodak agitation cycle time for tank development of roll films. I've also developed hundreds of sheets of xray films in many different ways, while visually tracking development, so I have developed (hah) sort of a feeling for what's happening at the film surface. Based on such experiences, I've settled on my present way of working.
I don't doubt that some form of stand development may work to an extent on sheet film as well. It's just very sensitive to the geometry of whatever the film is in (tray, tank, reels/hangers) during development. For instance, I've stand developed sheet film in a Paterson tank with a MOD54 holder and consistently obtained horrible flagging around the fingers of the MOD54, extending downward into the image area. Results with a DIY spin on BTZS tubes has worked a lot better for me - although I never observed any tangible benefit to this approach. It just takes a lot of time.