Please excuse the smartphone typos.
gota--> get a
There is no "legal test and a practical test." There are only the questions whether you can sue in the U.S. and whether you can collect if you win. Which is why I wrote that "[o]nly your own attorney can evaluate the facts relevant to the question and whether it makes any economic sense to file suit." The answers, for you, to the two questions that you need answered will be neither "legal" nor "practical" -- they will be the end result of applying law to fact to approximate what's best for you.