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You get better spring if you have a cast iron pot with a lid, but your method is the best alternative otherwise. As mentioned above, score shallow - I always over score and it comes out crap.
The amount of spring is also affected by the proof - you want enough proof so that the loaf isn’t dense with big holes generated in the bake, but not so much proof that there’s no more energy to rise and spring when baked. There’s other factors too, but too many variables makes identifying problems even harder.
I followed pollen bakery method, scorching hot oven and loads of water on a pizza stone. It stuck a lot to my proofing basket which could have caused it to deflate. I used proofing basket without the cloth, trying next batch with.