With most of my horses I like to do 3 X rail bounces 9-11ft apart depending on the horse and also depending on skill and what you are trying to achieve!
EG I like 11ft bounces to start with for my babies as they have a little more room so they can shuffle or extra big jump in! They have room to do it.
For my older and more exp jumper I like to set up first at 11ft then reduce to 9ft he really has to think listen and it makes him super sharp in front!
This exercise does help a horse achieve a better outline over a fence and I have found it to be a great confidence booster for alot, if used correctly!