If all else fails: you are right, we did not have the IR filter. The 22kg and reduction in VNE to 140 outweighed any benefit the IR filter would give us, and the backscatter from the white light (it is mounted side of the nose in front of the pilot as opposed to underneath) was enough to disrupt the NVG image - so off it comes!
We use side mounted white lights to light up the confined area nd a downlight. These really assist the crewman for his winching. We attempt to get very close to references for night winching and use a lot of look-around view, but for high winching like sunny is talking about, we would be using more NVG image. Like him, we are yet to have to do an NVG winch where we cannot find good close references.