4.15 tonemapper - is it possible to simulate old effects?

I’ve mostly been playing with numbers on the assumption that the brightness of a point light is supposed to be its actual lumen amount (which is what the tooltip claims). In that case, the default value for auto exposure ’ brightness’ is much too low at 2, and there seems to be little harm in turning it as high as it can go, at least until you decide what you want your brightness to be.