The Easter hatch a long is over for this year.
The cutest baby fowl contest is still open
https://www.backyardchickens.com/threads/new-prizes-added-12th-annual-byc-easter-hatch-along%E2%80%94cutest-baby-fowl-photo-contest%E2%80%94win-a-brinsea-incubator.1445522/
It is good to have anecdotal evidence!
You could find some published peer reviewed experiment papers but then in our climate, many do not believe studies!
Feather sexing by speed of feather growth works with breeds that are sexlinked.
First it has to be two breeds. The combination makes one gender have fast feathering.
Otherwise it does not work and is the same as a coin toss.
Feather Sexing Chicks
Color sexing chicks can be a difficult task...