That is a chunk of mopar gold! Did he mention how the Hotchkiss leaf spring shackles/hangers provide a small amount of rear steering? I suspect that would have been part of his calculous for 'snap oversteer". If you read thru the September, 1965 Master Technician Service Conference "Roadability and Handling" lesson, the Rear Suspension And Rear Axle Geometry section explain how this works.
Roadability and Handling (Session 214) from the Master Technician's Service Conference
Page 5 explains the reason the leaf spring pack sits relatively flat, this is to improve stiffness, deflecting rear end sway and improving the effectiveness of jounce induced rear steering.
Page 6,
Roadability and Handling (Session 214) from the Master Technician's Service Conference
explains first how the rear wheels move forward as the rear enters "jounce", ie when the axle move upward over a bump. The movement follows an arc produced by the leaf spring hangers.
Next, "Understeer On Turns" explains how this applies to highway speed cornering. With the same principle, while entering a corner, the outside rear wheel will set into a 'jounce" positioning, pulling the outside wheel forward and giving a caster effect to the steering as a whole. As the front wheels are turned, the rear wheels follow in a similar manner. This is what lets us setup for a corner and mash the gas to power out of it. If the rear wheels didn't pivot, they'd want to plow straight ahead increasing the chance for oversteer.
The engineer's point of snap oversteer is one I've pondered while considering rear sway bars in the past, particularly on my Volare wagon. A sway bar controls how much the body rolls in relation to the axle. Reducing that roll reduces the rear steering effect on this Hotchkiss axle design.
I have found KYB GasAdjust shocks do a great job at taming the live axle beast while not reducing the effectiveness of this rear steering ability. Happy reading!