Likewise here from the UK. Be polite and respectful and generally I've never had any issues.
Once I even had the guard - who before me had been dealing with a plane full of Chinese tourists - give me a knowing smile and a "I can tell you know what you're doing" kinda comment as he more or less waived me through. I guess being a white male native-english speaker helps a lot in those scenarios.
P.S. Global entry helps a lot in these scenarios and is (still? was?) available to non-US citizens
Once I even had the guard - who before me had been dealing with a plane full of Chinese tourists - give me a knowing smile and a "I can tell you know what you're doing" kinda comment as he more or less waived me through. I guess being a white male native-english speaker helps a lot in those scenarios.
P.S. Global entry helps a lot in these scenarios and is (still? was?) available to non-US citizens