I'd be perfectly happy with zdump gaining more display options, but I think there's still huge benefit in deciding on one
canonical format for validation. It means that single format can be distributed rather than everyone having to build and run zic themselves, just to get output that can be centrally distributed. (Even if it isn't part of the IANA distribution, I can host that canonical format - not ideal, but better than nothing.) With a to-the-byte canonical format, I'm also happy to put the SHA-1 hashes up.
As one point I suspect we could all agree on: assuming there is to be a canonical format, should we use "\n" as the line separator? (My current format uses \r\n, but I think that's likely to cause more pain than it alleviates.)
Jon