Lotus may be contemplating some sort of quick response variable turbo or supercharging to provide the “variable displacement” they are touting. Being able to rapidly modulate boost pressures could allow optimization for almost any fuel except perhaps diesel which would require much stouter internals than needed for alky or gasoline. It might well allow an engine to get the most out of whatever you are putting into it but the fact that alcohols have a lower energy content than gasoline simply cannot be sidestepped regardless of techno trickery.

Drag racers use it for its detonation resistance and heat removal qualities but they are hardly worried about efficiency in any sense that ordinary drivers are concerned with.

A highly adanced blown two-stoke might well have a significant weight advantage over a four-stroke of equivalent power. Dropping powerplant weight by a couple of hundred pounds or more would be all to the good.