Octopus routed over the left shoulder.

We both have plenty of room to easily swim in the same direction whilst maintaining contact. The OOD has unobstructed access to their LP inflator hose (as do I) and I have access to their shoulder dump if need be. A few months back I got to test my 'theoretical' benefits of this with a 'low on air' diver when we swam like this for 5 minutes to a safe ascent point very comfortably.