Something tells me, that there just has to be a difference. Yet I am reminded of things I was to memorize in order to pass tests back in school days, when I was supposely being "taught" various subjects. Were they "teaching" me things, was I "learning" things, or just going through an excersize in memory ? Things get a bit confusing to me as I try to determine what actually took place.I think there's a huge difference in training your birds to "memorize" their way home as opposed to "teaching" them the way home.
I am willing to concede that releasing a bird from the spot where the race birds will be released from in the coming weeks, does sound like an experience that could assist the bird in finding home faster on the next release. Not exactly sure what takes place with repeated releases away from home, that appears to improve the bird's preformance.