I’m pretty sure we’re on the same page here. I did the kata during a class I took with the founder of our organization (“Kaicho” aka Tadashi Nakamura). He told me (in a heavy accent ) “JR back straight” I straightened out completely, then he said “not that straight” so I rounded my shoulders a little, and I got “just like that.” Stylistic differences, but in the grand scheme of things, they’re slight differences. And I’m not sure if you meant it during the jump, but to make it seem like you jumped higher, bend the knees more during the jump. If you meant on the landing, absolutely. The block gets lower by bending the knees more rather than bending at the waist.