In my state NPIP birds are leg banded. It doesn't get more specific to bird than a serial number. Had leg banded birds for years now. They forget all about the band after few days.
I like the idea of toe punch for pen groups. Makes sense for ease of identification to pull birds from flock when it's time to set up breeding pens. Don't see a need to get much more fancy than that when in conjunction with long numbered bands. NPIP bands are something like 6 numbers long, it's very bird specific. With that kind of info you can easily record exactly who the sire and dam is of every bird. At least group of potential mothers per bird if setting up quads.
I like the idea of toe punch for pen groups. Makes sense for ease of identification to pull birds from flock when it's time to set up breeding pens. Don't see a need to get much more fancy than that when in conjunction with long numbered bands. NPIP bands are something like 6 numbers long, it's very bird specific. With that kind of info you can easily record exactly who the sire and dam is of every bird. At least group of potential mothers per bird if setting up quads.