Let me try a different way of explaining the issue.

Much of the time in the swing dances are weight is not balanced at a point between our feet, but instead must leave the position of stability over the standing foot before the receving foot is there to receive it.

To take one of the harder examples, imagine you are dancing waltz and have risen to foot closure, so that you are about to lower and divide your legs into a new step. A beginner will lower with their body balanced over their standing foot, swing the moving leg forward into an obvious heel lead, and then shift their body between their feet.

A coordinated dancer will do something a bit different. Their body will remain relatively stationary until their standing heel touches down on the floor. But as their knee starts to bend to continue the lowering, something changes. Instead of letting the knee bend forward of the body, the body rides forward on top of the knee, such that the front of the thigh stays almost vertical over the kneecap. Try this and you will find that at first you can maintain static balance (and thus dance the action arbitrarily slowly) by using the toes of your standing foot to support you. But soon the point of your static balance moves past your toes, and you must either fall forward or distort your body position to regain balance. Or do what we actually do in dancing, which is to speed the motion of the body forwards as it falls beyond our balance, so that a stumble becomes a gracefull swing. Unlike the beginner, this dancer will keep the moving leg behind during the early part of this process - after all, it weighs quite a bit, and having it forward of you will only make your fall into the step sooner. But at the right instant the moving leg begins it's delayed swing forward under the moving body, develops from toe drag to heel lead so fast you might not even see it, and catches the weight of the body as it arrives and swings through (and probably up) into the next figure.

Many teachers start beginner students with the goal of simply building awareness of how one is dancing, even if most of the details are wrong. Awareness is certainly a necessity, but practicing incorrect techniques may require a lot of difficult work in the future to counteract the resulting limiting habits. This still seems to work as an education model, because most of the students won't advance to the point where they are aware of the limitations those beginner habits create (though if they are otherwise doing well, it will be obvious to a skilled observer). Unfortuntely, quite a few teacher's own dancing is little more than a precise execution of beginner methods - perhaps stretched to a usage at a moderate level of competition in the past, but not possessing the fundamental details which advanced dancers use to execute basic figures.

I'm with Suonomynona. on this one. That is. "But as the knee starts to bend something changes". It is the flexing of the knee which brings the weight foreward taking the rear foot to the tip of the toe and pushing. Even though it is another dance with some footwork differences the Samba has the same action in a Walk. The bending of the knee brings the weight over the supporting foot.

"I'm with Suonomynona. on this one. That is. "But as the knee starts to bend something changes". It is the flexing of the knee which brings the weight foreward taking the rear foot to the tip of the toe and pushing."

I'm actually not sure we are on the same page at all. I am talking about the knee of the standing leg. The moving leg has not yet swung at this point, so it plays no role in creating this movement. Also the heel of the standing leg on a step 3 to step 1 transition will not lift until just before the moving foot is placed. (This is very different from a step 1 to step 2 transition, where upswing footwork means the standing heel must lift before the feet pass)

Surly the moving to the extreme part of the toe and pushing, By extreme I mean the very end of the toe of what will be the moving foot. It is all part of the question.

"Surly the moving to the extreme part of the toe and pushing, By extreme I mean the very end of the toe of what will be the moving foot. It is all part of the question."

let's play guess the subject noun!

I'll make it easier. Do any of us move far enough away from our rear foot which would enable us to use the whole of the foot and not just part of it.
Whilst we are here I have been watching a whole heap of Spin Turns. With John's RF. in between the ladies legs which are apart, the lady is straddling that RF and leg. Anne is up on her toes Backing LOD.Her feet are vey close together. He then goes past her with his LF. She appears to be standing still as he passes. Standing on that LF. It looks like split weight. He is moving.

"Do any of us move far enough away from our rear foot which would enable us to use the whole of the foot and not just part of it."

Probably not. Realize though that the primary benefit of using the rear foot with respect to travel can come only if it is used while the moving foot is still moving. If it is used afterwards it can not increase your travel, but only your body speed. Speed in excess of the needs of travel must become rise, or dancing looses dynamic coordination.

A more interesting case is to look at the backwards ation. Toe releases are often specified as part of using the whole foot. But here again, the part of the standing foot that is used after the moving foot is placed is largely wasted - it is the part employed while the moving foot can still move which brings true benefit. Watch men lowering from step 3 of a natural turn in the waltz. Does their right toe release before their left foot is placed? If not, they have not fully danced the action and have set the lady up for an awkward failure. Some will step to the side to spare her the full consequence of their mistake, but this is not dancing with your partner. A lady who made that mistake on step 1 would be laughed out of the final.

Suomynona. I'll try to keep this short. My experience is that people will not read a whole heap of writting, so most gets lost. Falling out of a Spin Turn.
If the lady has her feet apart on that 5th step straddling the mans right leg. Doesn't that give us a common center to turn over. If the lady goes too far down the LOD with that 5th step. Doesn't the man then have to chase the lady, making the whole thing very untidy and over stretched. Even worse in the Quickstep.

Dave. Contact point in the Quickstep between the man and lady is higher than in the Waltz and Foxtrot. Strong feet and ankles also come into this. One Lecturer had us take our shoes off and use the whole of both feet from the heel to the toe. If anyone needs proof of this try walks down the floor , all heels, and then bring the whole of the back foot into play and push untill only the tip of the toe is in contact with the floor. Keep the body verticle all the time. As you walk so shall you dance, some hardly get the back heel off the floor when they walk, and are most likely to do the same when they dance. Just about every time Michael Barr is the comentator at an IDSF competition he points out the strength of the feet ankles and legs.