(c) You do not know, nor do you measure what comes out of your filter, but you "know" that it's "good enough." How can that be?
Where did you get that idea? that I do not care what is before the filter does not mean I do not care what is after the filter.

How do you know what the converter does at Vin = 32 volts or when it's at 18 volts? What happens when the input goes from one to the other, particularly when it does that for only a millisecond or two?
Try that across a hefty defty lead acid battery. BTW we have a few that run on 9-14V without any change. Shuttle coaches run on 12V, full size coaches run on 24V.

Analysis has to come before design, you know. If you don't perform analysis, then what you do is not design. It's just guesswork. Surely you don't try to get by with that.
Of course, I do. I look at the datasheet and design. THEN I measure what comes after the filter to see if the combination works as expected. I have ZERO reason to do anything else. As opposed to you I do not assume that manufactureres are "out to get me"

Erik