I am only replying to show you that we do read these posts, unfortunately I do not ride a bike/scooter or tow a trailer. Also I cannot think of any member who has attended one of our meets in recent years who has had a bike trailer either.
Sorry not to be of any help on your question. Obviously you can get lots of information on the internet regarding regulation on foreign trailer law and bike/scooter reviews. No doubt you have already gone down that route.
Good luck in your quest.