Yes, udefuri choyaku undo was taught to us by Koichi Tohei Sensei when he visited New York Aikikai decades ago. I found it very useful to practice solo at home and I used it from time to time when I taught at a local Y back in my home town. We were lucky to have a two hour class, so after some basic loosening and stretching exercises we had, from various teachers and seminars I had attended several solo practices for basic Aikido movements. I would tell people it's a good idea to do these to practice keeping your own balance each class before dealing with another person
Within the two hours, we had plenty of time to do the regular partner techniques, plus some jiyu waza usually using whatever techniques had been taught that evening.
So, Kevin, good luck and whatever your dojo recommends for solo exercises, and thanks Ashley for your excellent explanation