Aaron Parecki

That's true, it's based around the assumption that clients display posts in a stream, rather than a model like email clients where only the subject line is displayed.

In practice you can't store just an ID, you need to store something else in order to give some indication to the user of what the thing is before they click it anyway.

In a similar vein as to what I think you're getting at, we do need to extend Microsub somehow in order to support "conversation" views. Think clicking on a tweet to see the full thread. I think that same mechanism could be used to lazily load a large post if needed too.