@christianbundy Message content as blobs is in the pipeline, can't do everything at once =)
The idea is one that is pops up regularly btw, the earliest mention I found was in an ssb github issue from the early design stages.
This is fairly orthogonal to the json problems. We plan on completely moving away from json anyways, but there are other good reasons for only signing a hash of the message content (that is what it all boils down to). I planned a whole post on this topic, so I hope it is ok if I postpone a more throughout response until the issue comes up when the discussion about general metadata design choices has moved to that point.