I agree that these are not the same. I think it is worth saying though, that they probably would not be used. I think in a final draft, a writer would find a more clear way of saying this. That does not mean it is wrong. I just think the same things can be said in a way that you do not need to think so hard to follow the intricate meaning. Let me try:
"From all the research that has been collected so far, here is what we know..."
So far as is known = extensive research
"From what we have gathered about this, here is what we know..."
as far as is known = this is what we (not the whole world style of we) know so far
What do you think?