That is close to what I described as Aiki a few posts above, but the OP said he wasn't talking about that. He was talking about yielding in an ICMA sense for a period of time to learn to feel what is being applied to you. Sounds like basic Aikido or paired-kata ukemi.
Now the question is, is that really in an "ICMA" sense if you are merely getting out of the way? If you are just all yield, but no enter, is this not actually training in an anti-pattern that you will simply have to unlearn to actually progress? As much as internal/external are loaded terms/dichotomy, is this one-sided yielding not just a pretty obvious example of the external, of the evasive movement style of MA? While the anti-pattern of resisting a force coming in most definitely and continually needs to be worked out of one's body, that does not mean it is smart to do its direct opposite, which is just another anti-pattern. The solution found in ICMA is outside this spectrum entirely.
In the example of the T-peg, what happens, if the peg moves out of way and thus "absorbs" the push by allowing itself to be physically translated in space, not rotated on its axis, or similarly tries to store the push by allowing itself to be deformed by it... that is, it really neutral anymore? Is it then really free to express yin and yang?
I don't think it falls into the spectrum of ICMA to train in a form of giving way as a response to force-in. At the very core of ICMA practice, we need to be working from the start on giving the force-in a way on
us that does not go into
us, we are neither resisting the force nor being affected by it, establishing neutral. There is scarcely a MA in existence that doesn't know how to evade the power of an attack in this manner - even boxing has the rope-a-dope, neither is that the expression of yin and yang we should be seeking.