I’ve got the XTR Rear mech set up on my road/tour/cross bike in a 1×11 setup. I’m using Ultegra 6770 levers with an EW90A junction with no problem, so I think you will be fine to use this instead of the XTR display.
The junction also works fine for charging, updating firmware and telling you battery status. It gives you indication of 100%, 75%, 50% and 25% remaining with red and green lights.