This is an excellent step by step instructional of the mawashi geri.

Is the ITF TaeKwonDo ball of the foot dollyo chagi any different mechanically, and if so how?

The difference that's quite striking to me is that, in the OP video, is that the supporting foot is NOT turned a full 180 degrees from said target. That disturbs me, but Shindokan isn't any form of TKD, however, GM Young Ik Suh TAUGHT like Shindokan does when it comes to the supporting foot rotating fully that 180 degrees away from said target.

To each their own!!

We believe that the power apex is cut short to completion, therefore, power is diminished!! But, that's our methodology.

That's very different to mawashi geri I learned at wado, and is also very different to tollyo chaki from TSD.

The mawashi geri I learned at wado is almost exactly the same as instep version of tollyo chaki.

What we see in the clip posted looks very like a drill we have at TSD, which is absolutely not the kick. The long stances, the straight arms, looks like an drill we have to train balance. It's a perfectly good drill, as long as folks recognise the difference between an exercise and a combat move.

In my TKD days, GM Suh taught both the ball of the foot and the instep, and so does Shindokan, however, Shindokan favors more of the instep to the legs.

Oh to be young and supple! (Young I once was, supple , never!)

We also learn to pivot only to 90 degrees to the target.

Deep stance also, don't think I would get there from such a deep stance.

Oh to be young and supple! (Young I once was, supple , never!)

LOL!

We start off learning round kicks with the instep. Eventually (blue or red belt?) we use the ball of the foot.

That's very different to mawashi geri I learned at wado, and is also very different to tollyo chaki from TSD.

The mawashi geri I learned at wado is almost exactly the same as instep version of tollyo chaki.

What we see in the clip posted looks very like a drill we have at TSD, which is absolutely not the kick. The long stances, the straight arms, looks like an drill we have to train balance. It's a perfectly good drill, as long as folks recognise the difference between an exercise and a combat move.

You are spot on ,this drill was not so up to mark , hands are almost redundant where in reality they are an important part of executing a meaningful mawashigeri ,stance are too long and hence slowing the technique .

It is about learning the most efficient way to execute the technique and how to hold your guard and move your hands to the opposite direction of the kick to release the hip into your kick thus producing more power and how to initiate your move from the ball of the supporting foot by twisting it in harmony with your hip and the kicking leg.

Even in the most basic drill all these should emphasised and concentrate on to develop a good technique .

If it is practiced correctly over time and effort even someone with no natural suppleness could execute a powerful mawashigeri and they don't all need to be jodan or head high to be effective.