OK, I lied. I CAN fold the ROPS all the way over with the lights mounted - it's close though. I've never tried it because the backhoe has been on most of the time, and I can't fold the ROPS all the way over with the backhoe attached.
But I tried it today now that the rear blade is on for snow season, and it will fold all the way over. The lights are right up against the rear fender.
Since I never fold the ROPS beyond half way, I didn't bother to set the lights up for the full fold-over. If you add lights, and you fold your ROPS all the way over, just be sure to make sure you've got enough clearance when you're fitting everything up.