can you think of a technique that depends on speed to work, and when done slowly, would allow uke freedom to reverse or escape without danger?
Maybe I don't understand, but I'm confused. It seems to me that the speed of a technique is negotiated between uke and nage as they both 'agree' to move at a particular pace. If uke wants to go fast, I think it would take a very skilled nage to keep things slow. Likewise the other way around. One of the training 'agreements' in Aikido is that both partners respect the speed at which the training is happening. If uke starts slwo and then suddenly changes gears, it is very hard to practice effectively.