BTW NC
In addition to there clearly not being a halacha that 13 year olds shouldn’t wear a talis. The very minhag that prompted this thread namely Gebrokts is also not “how you and your group hold in the halachah.” To the best of my knowledge nobody holds “in the halacha” that Gebrokts is assur, (nor kitniyos for that matter, though perhaps since it is such an old minhag the minhag status is somewhat elevated, but nobody holds that if you go through Pesukim, Shas etc you come to the conclusion that kitniyos is assur on PEsach)Nor does anybody hold l’halacha to have a proper kapara you need kapparos before Yom Kippur.
There are dozens of minhagim that are not “how you and your group hold in the halachah.”