I’ve had an e locker for about 9 months now. Haven’t noticed any difference in fuel economy.
If my understating is correct and from what I have noticed, , you still have power sent to both wheels at all times much like a standard lsd (especially an old worn one), only when you break traction will the power naturally go to the free wheel.
In short, the car feels exactly the same as what it did prior to the e locker. Only difference is you can now lock it when you want!