Not wanting to get in between the Ki Society/Aikikai tango here (God knows we're already the Aiki-heathen
) but returning to something that Craig said in the "kotegaeshi weakness" post - doesn't the application and maintenance of effective kuzushi automatically take up any slack that exists on the attacking limb while one applies technique?
In our training the ability to eliminate holes for Uke to recover (especially in the form of things like slack) is very important in making technique effective. However, we don't exaclty focus on this "taking up of slack" concept as it's contained in the practice of creating and maintaining kuzushi.
Just a thought I had.