I propose that the practice of “circling” is independent of the T1/NT+T2 debate. Steve asserts that circling can be used to provide T2. Yes I can see myself doing some light circling in my own classes, just to expose them to a word needed to understand the story. Circling is a tool independent of the input chosen. It can be heavy or light.
In NT+T2 light circling would be used (I do, asking two or three questions) to reinforce new language elements.
In T1 heavier circling would be used to make students “acquire” (whatever that means…how would that be ascertained?) the “rule of the day”.
I propose that TPRS trainers are so adamant that the heavier circling be present because they are doing T1. Many trainers have asserted to me (quite passionately) that teachers wishing to provide CI must first proceed through a “Circling Phase” to get the skills needed to provide NT+T2 input. The hole in this logic is that they only say that because they are conceptualizing CI as getting heavy repetitions, and thus a way to provide the massed repetitions is needed, which is exactly in line with the original definition from summer 2016 stating that T1 is CI with massed reps. That is the position they are operating from.
I used to teach that way as well. Now I have taken up NT+T2 as my goal and I can therefore see a different perspective. The “Circling Phase” is only needed if the goal is to provide concentrated massed exposures. It is not a foundational skill to speaking comprehensibly.