It appears that "Caribbean Netherlands" (https://en.wikipedia.org/wiki/Caribbean_Netherlands) is missing from the list of valid countries. Can you correct this?
Generally, many countries, especially in the Caribbean, have "alternate" spellings. Having to filter for each of these, while bearable, causes unnecessary steps. I would like to propose the introduction of "aliases" for such countries (for instance, "St. Kitts & Nevis" is to me a perfectly acceptable and unambiguous alias for Saint "Kitts and Nevis".
Since I believe I am not alone in collecting data from Google Analytics, accepting their country names as alternate spellings would simplify data analysis for many users. In a global data set from Google Analytics, I had to replace about two dozen country names because of this discrepancy.