[NanasBack]

A bit of Googling and a rough calculation:-

400HP diesel engine uses around 100 litres / hour.

which is 2 litres / min
or
30ml per second.

I wouldn't know what degree of effect that filter would have on such a rate.
It's probably not good?

Maybe there are pressure difference or flow monitoring systems which would throw codes. Maybe experience has set the change interval period.
Dunno.

Edit:
Fuel and air filters were changed on the second service (36k) of my 335d.
(Idrive service indicated).
The previous E90 325d, I think was nearer 60k. Certainly for the air filter.