This is a very good paper and you’ve presented it very well. In my opinion, the capacity at the points of entry to detect and prevent Covid-19 could be a potential parameter. Another potential indicator could be the density of airports/seaports/land borders in a country to the passengers. However, those parameters may be disproportionate as each entry point in a country has a different capacity level and different influx of travelers.
If I were the policymaker, of course, this risk stratification and assessment is one of the considerable steps. However, when deciding to disclose or keep close the border, other important socioeconomic aspects should also be considered as some areas in the country may have a strong dependency on economic activities and supply chains for food.