The difference between くらい and ほど in hyperbole?

Question

The following two sentences, I believe, are grammatically okay, however I'm not sure on how they differ in nuance. もう歩けないほど疲れた！ (もうあるけないほどつかれた) もう歩けないくらい疲れた！ (もうあるけないくらいつかれた) Additionally, why is it that: 死ぬほど恥ずかしい (しぬほどはずかしい) is grammatically okay but 死ぬくらい恥ずかしい (しぬくらいはずかしい) is not? (However 死にたいくらい恥ずかしい is okay.) From looking at this, it seems くらい cannot show volition. Is there a logical reason for this that I'm not seeing?

Answer 1

KURAI cannot he used when the degree is extreme. Physically dying is extreme, but wanting to die is not.