Very interesting response Double Bogey from someone who obviously knows this environment. It is clear night rig approaches in VMC can transform from being relatively straightforward with good visual reference with the platform on approach to being really tricky on a go-around when the lights are gone and it's just inky blackness - and at low level. Hard to think how this should not automatically require an instant transition to instruments.
I too have had my most anxious moments in the potentially fluctuating transition phase from IMC to VMC flight when flying SPIFR on an approach. Letting down on instruments on a wet misty night can be reasonably straightforward until you become visual. At that point you are really reliant on continued vision of ground lighting and if that disappears - either because you've passed over what you were looking at or denser rain or mist is hindering visibility, it can get very difficult and all you can do is pull back up, get back on the instruments and rapidly climb to safe altitude and plan again. There is the added danger that if speed reduces with a flare on initially becoming visual, if that visual reference is lost the airspeed may be dropping below minimum IMC speed, especially with a rapid cyclic pull back to maintain obstacle clearance on reverting to instruments.
Is there a policy on night rig approaches even in VMC of the PNF following through solely on instruments, so that if the PF calls go-around the PNF can smoothly and calmly take over, already fully orientated on the instruments? Assuming Radalt monitoring in the scan, this would have the added benefit of safeguarding against disorientation on the approach.