I am not the expert on international diplomatic law, but I can say that, in general terms, this issue was also raised in the other place, in a related bill.
There is a spectrum of property that can be owned by a government. Some of it can be commercial and may be subject to certain activities, but some of it is of a more “state” nature. The most classic example is diplomatic property, but there are others. Central banks are another question. It would be a violation of public international law to have seizures of that property.
