Collision for mounted players

It's one thing to die from enemies, a bad fall, or burning in lava, and a completely different thing to die from suffocation while riding a mount. Please add player collision while riding, whether swimming on a nautilus or riding a horse. It is not uncommon for the character's head to clip inside a block, but it happens especially often when you switch from a warped fungus on a stick to another item—the strider wanders off somewhere, and the player starts suffocating. This has become particularly frustrating ever since the suffocation damage inside blocks was increased.