At the dropout? I’d say that’s normal in real life, but I’ll check up on that. It’s not a great design tbh, I’ve seen more than a few frames written off by excessive wear that has ovalised the pivot housing.
I think its the same with everything, customers dont look after bikes, are unfortunately not aware of things and dont check them.. the few write offs I have had have been serial bike wreckers. I like the design, it works.
Brompton list 2mm as the maximum acceptable play.