Odd that

dig A0.0,0.0/0.0,90.0.aerial @dns.toys

and

dig A0.0,0.0/90.0,0.0.aerial @dns.toys

both produce TXT "aerial distance = 10007.06 KM"

The equatorial circumference is 40,075.017 km (24,901.461 mi), while the polar circumference is 40,007.863 km (24,859.734 mi).

I guess there's no great harm in assuming the earth is hypothetically cow shaped, and it avoids that awkward series for shortest distance twixt points following an ellipsoids surface.