Thanks Genny. I tried the mia_exposure_photographic and but some of the settings got lost in translation. I used ies light profiles on most of the spot lights and from what I can figure out the cm 2 factor settings of the profiles have an impact on the exposure node. I ran out of time to experiment further so I had to resort to just adjust the light intensities.

Still on the dark side but I prefer it like this.

PS. The 18% for exposure and now in the digital age a 90% white card for white balance.