So some people have issue with Adopted Ancestry requiring third level, when it should theoretically have an impact earlier. What if, instead of it being a general feat it is a "universal ancestry feat," this would obviously be a home-brew that i don't think would be too broken. I don't mind it too much but I wouldn't mind providing this option for players of mine who do want that significance at first level.
It takes away one of the things that makes humans special as an ancestry, and actually indirectly reduces the 'special-ness' of ancestries generally since every dwarf could secretly be adopted by gnomes or something (I don't love the dwarf ancestry feats and do love the gnome feats).
One option is to consider looking at making/extending half-ancestry heritages for other ancestries (like half-elf/half-orc). The core rules have a little sidebar mentioning possibly extending those two to other ancestries, and it wouldn't be that hard to create similar ones for other ancestries.
Or, if you don't like idea that all your players are suddenly mixed ancestries when they're just supposed to be a goblin orphan found and raised by a friendly gnome family, you could make Adopted Ancestry literally just a heritage. It's clean, simple, and makes an ancestry actually give up something of value while still letting them benefit from the feat at level 1.