Planar Reflections and Physical Lighting Units

Hi first time posting here, have been using Unreal at work for a year and a half now and really getting into the rendering side of things.

I’ve been exploring a physical lighting units workflow for a project at work with overall good success. I can look up camera exposure values, and lumen values for lights, lux values for the sun and get expected results overall which is great.

However the planar reflections feature does not seem to respect the exposure settings of the scene when dealing with real world lumens and lux values and manual camera exposure values. It would seem to be behaving as though it were rerendering the scene without the manual exposure settings being accounted for correctly. It glows hot white. I think it’s glowing because I have convolution bloom on, but point being it is reflecting super bright values.

I hope I am just missing something obvious but as far as I can tell I’ve ticked all the boxes I can think of so to speak so if anyone can shed any light on this that would be awesome.