The Spanish will accept it and just look for ways to get around the law.
For years the law was that you couldn’t smoke on the metro, and that’s how people read it, on the metro no smoking but on the platforms yes! The motorcycle helmet law said that the rider had to carry a helmet, just not necessarily on their head! I sometimes go to a retaurant with an enclosed smoking area and the dividing door is left open allowing the smoke to drift into the non smoking area. 😯
If I remember correctly, the last BA flight to allow smoking was Madrid/London/Manchester-so yes, smoking is/was quite important.
Then there is need to police the law, I’m not sure how it will be policed. But the law has to be strong otherwise the Spanish will simply find ways to get around it.