PALKIP

post_piercing_attack was hardcoded to ignore players with 6 hunger points or less in survival too, and now any datapack with custom enchantments (that use post_piercing_attack) wont work correctly, this isn’t just a creative problem

I checked, for some reason the player's FallDistance is 52% higher than expected

No, in this case the delay affects only projectiles that display a direction, like arrows or tridents, snowballs are not affected, also the method used to change the projectile's Motion does not influence the update delay, the only method that seems to update the arrow's displayed Motion correctly is TNT's explosions.