You really need to read posts in the context of the thread. It eliminates the need for unnecessary explanation.
Obviously, I am not talking about training single techniques with uke blocking them and nage forcing through. That is not martially effective and it is not aiki.
I am talking about dropping the uke/nage roles and giving each partner a goal to achieve while stopping the the other partner(s) from achieving their objectives.
I'm not sure why you are concerned with a referee. The vast majority of my training has been outside the presence of a referee and has still been very useful.
It's not difficult to come up with rule sets that allow for this to occur.
Not that it matters for the exercises that I was describing, but once you are acquainted with aiki you can easily see it occur.
Here is an example of training we do. I'm not refereeing as much as serving as a control measure.
I define the constraints in order acheive the training objectives and ensure safety, however, it is non-compliant and they are free to pretty much do what they want in order to "win".