I think it would be useful in various situations. In my particular case clients of different quality are connecting to a local datastore. I'd like to make sure

I think it would be useful in various situations. In my particular case clients of different quality are connecting to a local datastore. I'd like to make sure that even if they mess up validation the data in the store still matches the schemas it claims to. Of course, I could have them connect to a local process instead and have that process handle validation before the data goes in the store, but it's always nice to avoid intermediaries.