The Avro RJ series of aircraft have crosswind limits of about 15 kts; however the manufacturer demonstrated considerably higher; I recall 30 kts being quoted. The Flight Manual limitations represent the statistical probabilities in having to maintain a very high level of safety in Cat 3 conditions; possibly higher than for manual landing? The Avro has a super soft autoland without sacrificing head or tailwind limits imposed by the requirement to land in the official touchdown box.