DFC :
First......... to one and all a safe new year.......
I fail to see the connection to flying at FL350 with regard to nav lights, and I very much doubt that pilots flying in that airspace will come to the Pprune private pilot forum to verify any SOP or legal requirement concerning this subject.
When I do get tangled in these discussions here I try desperately to argue my positions based on common sense and good airmanship, none of us could possibly read every rule and regulation....even if we did there are deliberate grey areas built into them to protect the regulator, that is why you get so much disagreement between people because rules are deliberately written to confuse.
Chuck E.