I think it the current solution is quite good. First card payment in a new country gets declined, and the app asks you if you want to allow that country.
Location based allow/not allow comes with a lot of complications, like incorrect location reported, being on VPN so you can watch US Netflix, having your boyfriend using your second MasterCard at home while you are abroad etc.
Better as it is now, to just block new countries, but provide an easy way to allow them on first decline.
One thing though, that might be helpful. The app detects that you are in a new country, checking for this every hour or so, and as soon as you are in a country that is not on your allow-list, you get asked once if you want to allow that country.