The C1 Wingies were released as part of the Creatures Community Spirit Festival 2016. They use partially implemented code that was used in C2 to make tails but was unused in C1. This code was used to add wings to the Banana Norn, White Haired Pixie Norn, and Horse Norn. They also contain Jessica's baby male norn body data fixes.
Their author is Allekha, who said:
I don't recommend crossing them with norns that have body slots 3 and above, as it will look strange due to the body data not being there (yet).
They should crossbreed okay with non-winged norns; however, they may not inherit all of the pose gene edits and so might not move their wings as much.
Perhaps that's realistic, the crossbreed not quite inheriting everything they need."