unique enchantment for chestplate

All Minecraft armors have a unique enchantment except the chestplate. And I want to change that. I have two ideas that I think fit in the game.

1. stability: 1,2,3,4,5.  
reduces knockback from attacks. similar to netherite, but as an enchantment. 

2. stamina: 1,2,3.  
slows down the loss of hunger while jumping, swimming, or fighting.