Yes I know that, but to be frank, the value of the rusted part isn't much, up to that point its a strength/rigidity/performance discussion.
If, say, the Brompton steel rear triangle is rusted to the point a scrub and paint isn't enough it costs about 110ukp to replace and instantly remove any hidden damage.
So Titanium's anti-rust features aren't important.

I bought Ti for simply easier to carry the folded bike. So back to my question - what is the impact on comfort and performance?