The article that started this discussion is a case in point. "Europe added almost 23,000,000 km^2" or "Europe added almost 9,000,000 mi^2" are both approximate statements. An automatic conversion would give an unwarranted impression of precision in this case.
Just add a ~ or ~~ before the number to indicate the degree of imprecision and the converter finds the best approximation.
Regards,
Erik