I can not find it now - but sometime ago I saw a video of a very strangely muscled TWH - a Chestnut I believe. He started out barefoot with a rider on. WHen he moved off he seemed stiff and unsure - not very well gaited in that he was very heavy on the fore. Then they added stacks and weights and the chain and he did his squat and spread.
And I knew why he was so stiff and off in his barefoot gait.
I bring it up cause I heard sometime ago from folks who like to stack em that the stacking thing started NOT as something you would show in a ring. Instead it was a training option (like a dumb Jockey would be a biting option). Once the undesired gait was broken up with the stack or weight - they took em off to train. It was not initially meant to be how the horse was ridden and kept.
But as to the chestnut I referenced - the loss of gait and need for retraining when barefoot was a good example of why the entire stack em chain em thing needs to go. It does neither the gait nor the horse any good.
IMO it becomes a form of hobble.
Looking at the above video, I see lots of unnecessary torque on those stifles and hocks at a time when the horse needs to be let to grow mature and strengthen... why blinker him? why do that to his tail? on top of the horrid bit and spurs??? All that crap on the front legs - pure ignorance.
Really sad stuff being done to a nice horse.
Soon it will all be illegal.