[feature request] brighter lights

Hello, 

I'm using Stager to light a scene and I want to place a large area light, to give some extra ambient light. Unfortunately I can't because the exposure is capped at 15. I understand Stager is trying to keep things simple for the user, but if there was a way to unlock it, or activeate advanced settings, closer to what Arnold for example does, that would make it a lot more usefull. A Kelvin value for the lights would be great as well.