Less so if you assume the cryptographic hash will be truncated to 32bits so that its size matches crc32c. Furthermore, some of those collisions will be on mess

Less so if you assume the cryptographic hash will be truncated to 32bits so that its size matches crc32c. Furthermore, some of those collisions will be on message pairs with small hamming distance, probably including messages with a single bit flipped which CRC will always detect.