Hi Paride,
it looks like using limit to camera mode in itoo and animated moving camera kills octane eval times. I think octane refreshes every single itoo in the scene every frame because of it. Animated camera makes eval times way longer.
We are still trying to figure out why some scenes get eval so fast with itoo and some take 40 sec or so. I am not sure what's causing it and why. Same scene can act differently depending on the camera angle.
UPDATE:
it looks like if you add a camera to the CAMERA tab in itoo even if you dont use it octane will rebuild all itoo forests every frame