Sorry my brain stopped working. The Nissan X Trail and Mitsubishi Outlander are basically the same car sharing the platform with different engines and transmission for different markets. In theory there is nothing stopping Nissan using the 2.4 litre engine and 20kWh battery as fitted to the current Outlander PHEV sold in the Australian market.
Your right they could, however, I think this whole idea of of using the engine of a generator is prety clever stuff and maybe the next step?
Is this Outlander model available in the UK.