Interesting article! So, the role of "UX for physical world" is either an architect or an interior designer (when working with physical spaces or buildings). I've worked as an architect for years, and there are many parallels between UX design and architecture, that in my career switch to UX have served to my advantage. However, becoming an architect is a long and laborious process that in my country (UK) takes 7 years. It also removes the joy of being able to iterate and see clear measurable improvements to your product - once a building is built, this is it! (Although you may be more easily able to move around signs in a shop). :)