I always scan the description see if there anything important, no keywords jumped out at me, I skimmed over it (I guess because the sentence is so short and all but the word methodology have no significant meaning, so it didnt register as an important sentence I needed to read fully)
I feel like it'd be better to allow the line to pass over the sea so long as it ends up at the furthest away bit of the country at the same latitude, that even excludes the archipelagos in the same way as the original method as it’s unlikely there’s another island at the exact same latitude and if there is, it’d likely get crowded out my all the places where there isn’t another island.
As an example, the distance between the easternmost and westermost point in Austria is roughly twice as long as the distance from North to South (650 vs 300 km), so it should rank pretty high. It's surprising that its neighbor, Czech Republic, gets included despite being "taller" and less wide.
Fun idea for a quiz, though.