Here is a topic that I have not seen discussed in a while: with any point of divergence after the beginning of the Imperial era in 27 BC, how much territory can realistically fall under Rome’s rule? Germania? The entirety of the British Isles? The entirety of Europe? The Arabian Peninsula? Ethiopia? Persia? Even further east and south? Secondary question: what would be the economic, religious, political, and social impact of the Roman Empire achieving whatever you believe to be its maximum border, both on the conquered territories and the core Roman provinces? How long would it last until partial or total collapse, or at least serious territorial shrinkage?