I think with this mod you should try and disabled the throwing aspect of minecraft eggs and your eggs to spawn a chicken.

Its in the newest version

I like to keep my mods highly customized so it could be an option in the config, but something like that would default to vanilla, only because in modpacks ppl may not use hatchery correctly. But I like the idea.. it makes sense.

Will be in next version... just check config file to change.