The whole diffuse strength <-> IDL Intensity balance needs adjusted as I'd latterly understood what BB to be saying in that thread back in November / December?

i.e. why everyone started experimenting with much lower IDL intensity... e.g. down as far as 1.5, to compensate for the fact the diffuse channel was blowing out?

Maybe doesn't need adjusted as much as the defaults need fixed?

A global / master diffuse level setting in the render settings might be useful too?