Hi Beppe,
I understand what you´re saying.
But why is your file rendering fine (without the transfering issues) and why is the brightness so equal?
You disabled the C4D "OctaneDayLight" on the C4D-Side (thats what you meant with "just use the node", right?).
But when I disable that in my initial scene the brightness is still very different. Also I don´t know what was wrong in terms of the layers (sure, I used some tags that weren´t needed - but they also weren´t wrong in my opinion).
Why did I have those visibility and brightness differences?