I'm curious, too. Particularly since the mingmen is just the backside of the dantien. Even the statement is an oxymoron to anyone that knows how.
Bump. This has got to be about the 20th archived time (at least) in the last 4-5 years that a serious and germane question has been asked about a supposedly knowledgeable assertion, resulting in silence or avoidance. Very easy matter to discuss, as a number of people/lurkers are aware. Regardless of peoples assertions about what they can do, all we can *meaningfully* do in a written forum is discuss how's, facts, and so on. When it comes to I.S., there is a codified viewpoint that goes back very far in history (Ueshiba constantly referred to these traditional writings). If the conversations are reduced to other matters, personal observations about "some people", "senior experts I've astounded", etc., we go no where.
In regard to another topic, Ashe's video: Ashe, let me see if I can get you on the same wavelength. In your video you have a guy leaning in and *downward* (hence his force is pointed down toward your feet, for the most part). Your arms are moving. I'm very used to these scenarios and I don't see any dantien usage (you say you don't use dantien, so 'check'), nor are the hips meaningfully engaged in the movement of your arms. How are your arms moving? How does it work?
The actual limits of the dantien controls are bordered by the perineum, the front of the dantien, the mingmen, and the diaphragm. I.e., the mingmen is more or less 'the back side of the ball' that is the whole dantien region. The dantien area can be thought of as a, ummm, let's say a muscular ball attached to the base/lower-end of the spine. So anyway you look at it, whether an art is Shaolin or one of the Neijia arts, if it mentions using the hara/dantien then the dantien exercises control over movements. When a CMA expert says "no dantien", he means that someone is using local control, regardless of whether they've built up some level of rudimentary jin (no matter how strong), etc. One suggestion I often make, in an honest attempt to be helpful, is that people analyse their movements, particularly starting with the shoulders, and honestly evaluate where motion is originating, and so forth.
Because your partner is leaning downward, you are indeed taking a portion of his force to your feet... it's pretty easy to do in that position with a downward vector. But IMO you're going to be blocked for a pretty long time at that level of performance if you don't get someone to show you how to change the other factors and re-pattern your movements accordingly.