Ancestral Wrist and Warm Nest - no level cap any more. Each level costs a little more than the last, about what it cost before up to level 10.

Deep hatches - from shell 4 on, a hatch pays extra feathers that grow 4× a shell, as fast as the eggs get tougher, so your perks keep up.

Golden Hen Rumors and Golden Genes - golden eggs now take the place of plain, brown and speckled eggs only, so Eye and Void Eggs keep their odds and the golden upgrades always raise your yolk.

Hatch dialog - in deep shells it says most of the feathers come from the shell's depth, so there's no point waiting.

Big numbers - past the last suffix they show as 1.23e45.