I have noticed that Rect lights do not work properly when you assign a IES profile, it becomes a punctual light.
So I tried to emulate the effect using the barn angle and length but those options only work on stationary light but not static lights.
Notice in the picture the different results between the static and stationary lights and the same lights when using the IES (on the lights with IES profile I turn the barn length to 0).
Am I missing something? If not, can this be implemented for future versions of UE?