Mine’s been in for its MOT today, last year one advisory for corroded brake pipe covered in grease so said to garage if the pipe needs doing fit it and then test. Car was delivered back an hour later with a pass and the same advisory.
I think corrosion advisories are very subjective, one tester’s advisory is another’s straight pass, surface rust is just that so not affecting structural integrity. Most of the suspension and chassis components on these cars are built to tank standards.