If you have a piggyback FAA PPL it is not good for flying at night in the US unless the licdnce on which it is piggybacked allows night.
We all know someone who has flown at night without their UK licence allowing it, maybe been checked out - but it is not legit; to a US school a PPL without night makes no sense so easy to see why they get it wrong sometimes.
What is proposed it to let someone loose to fly at night with no training.