Good stories, and thanks for the history. We have a teacher at the dojo who loooves sutemi waza... maybe I'll have to have another look at it.
Another thing about sutemi waza...well, two things...come from flying.
When I was young, I got my pilot's license. One of the first things my instructor told me was to do no stunts in the little Cesnas we were flying. They had little gyroscopic instruments and if you did loops and rolls, you could "tumble" the gyros and ruin the instrument which would cost hundreds or thousands of dollars to repair. Once the gyro had tumbled, the instrument wouldn't work and the gyro wouldn't go back to normal operation.
Some people talk about aikido as gyroscopic movement, but sutemi waza will "tumble" their gyro and it may take them awhile to get "untumbled," as it were. Doing sutemi waza vastly broadens one's range of "controlled" positions. If you can only be "gyroscopic" while on your feet, your gyro has only one plane of operation. But if you can maintain center through sutemi waza and get back to your feet without ever having lost your orientation, it's a good advantage.
Another idea from flying is the Lomcevak maneuver, which is not a commonly known aerobatic technique. It's similar to a snap roll, which is a horizontal corkscrew maneuver, but in lomcevak, you add a control movement at the beginning of the snap roll and the airplane tumbles end over end, and falls hundreds of feet. It looks impossible to perform intentionally and impossible to recover from, but you can do it intentionally, and you can recover from it. There are several ways to do it and, apparently, it works a bid differently for each kind of airplane. This clip shows several examples:
By the way, lomcevak
means "headache maker," which might also well apply to sutemi waza--at least for the attacker.