This modification isn’t specific to jumpers, but I find that they are the ones I am most often putting them on. Occasionally, I put them on dressage horses as well.
Extended heels, or trailers are useful to effect the timing of hind feet. They can delay the heels from leaving the ground for a fraction of a second, changing the horse’s gait.
Hopefully, I’ll get a chance soon to video this horse or some other one in action to show what is going on. This particular horse came to me shod this way, so I continue the way it is.