"I suppose this gets a little scientific. There has to be a point where the weight is equally balanced, when it is just as far to the front as it is to the rear."

Only as long as you nievely assume that the weight is always supported by the feet.

If you actually look carefully, you will see that the body spends a lot of time outside the footprint of what is at that point in time the only supporting foot. During this time, the body is receiving some support, but it is also in the process of "falling over" (however, usually without leaning or pitching).

It is no great stretch to go from partially falling in those numerous, lengthy off-balance periods to contemplate that during the so-called weight transfer, it is entirely possible that there's a point at which, briefly, neither foot is supporting the body.

It's quite obvious that this occurs in the quickstep... in the other dances, depends on who you ask, and perhaps who they are looking at.

One thing of which we can easily assure ourselves though is that any period of split weight is limited to the frame (2 maximum) of video where both feet are arguably stationary.

"Both feet must be on the floor."

Indeed, that is a precondition. But the precondition you miss is that both feet must be STATIONARY on the floor before split weight becomes possible (otherwise you are sliding a weighted foot, perhaps popular amongst retirment age social dancers but unheard of amongst trained ballroom dancers.

"Which goes straight back to that other discussion which was lifting the foot off the floor, no contact. Does that make sense or does it not."

It makes sense, but since you can't weight a moving foot without doing something very odd and dispruptive, split weight is equally unlikely regardless if the moving foot is actually on the floor or slightly above it - it is still a moving foot and not a standing foot. The presence or abscence of floor contact would only matter if you tried to make it a second standing foot. So you argument only concerns preserving an ability to do something THAT YOU SHOULD NOT BE DOING ANYWAY.

A clock. The big hand goes from 12 to 6. It has to pass 3. which is split weight, an equall amount each way.
Another one that usually starts an argument is. The weight is never over the heels. I was told that once. Then I asked how do I go from one step to the next without the weight at some point being over the heel. Its not possible.
To get back to split weight, or equally divided as our technique books say. To do this and have an equall amount of weight over each foot. Here it is. Both feet must be on the floor. Which goes straight back to that other discussion which was lifting the foot off the floor, no contact. Does that make sense or does it not.