Any one who thinks the “N” plate is a flag of convenience is sadly mistaken, some parts of the American system are more flexible in terms of implementation but the emphasis is on those within the industry to comply rather than having the state regulator policing the rules closely ( and usualy inefficiently ).
Get caught breaching the FAA regulations and the American leagal system will show no mercy for those who think that just because the regulator is on the other side of the Atlantic they don’t care what you do .