I'm looking forward to meeting you and the others in the dojo.
There doesn't need to be much of a lift to stop the flat rotation of uke's fall that you're describing. Tori's timing causes the uke's own leg thrust to create this lift. Again, it doesn't need to be much at all. Once you see and feel it, you'll understand easily.
I'm off to the International Jodo Federation's triennial gasshuku this next week so I'll be "off the boards" from tomorrow until after the 30th. Lots of us from the Jiyushinkan are going and will be getting mega doses of Shinto Muso-ryu.