Another problem is making "digital asset" the object of the regulatory restriction, which is so vague that it could include not only anything on the blockchain,

Another problem is making "digital asset" the object of the regulatory restriction, which is so vague that it could include not only anything on the blockchain, but plenty of non-monetary digital items outside the blockchain too. It should specify digital currencies, because that is the only type of digital asset for which you find comparable regulations in the financial sector.