This means the protocol can accommodate an increase of an extra 53-58% in txs (and that includes dust and spam txs like the ones we have now).
This is faulty thinking. We will start to experience serious issues well before 100% and user experience issues even before that. Already several times we have had two full blocks in a row and possibly other times more that I don't recall.
It is not enough that transactions occur eventually, they should also happen in a timely manner.