I'm not entirely sure I believe this claim. Ergonomically poor surroundings typically force you to change your stance often, because you get uncomfortable quick

I'm not entirely sure I believe this claim. Ergonomically poor surroundings typically force you to change your stance often, because you get uncomfortable quickly. And in the long term, moving around a lot is generally better than standing still. I suppose if you always sat in the same café in exactly the same position and got used to it, you might eventully develop problems.