The niche bullshit will continue until… Well, actually it’ll continue indefinitely.
https://www.printables.com/model/791788-pilot-parallel-cap-with-pocket-clip
I just got done solving my years-long festering irritation with my spread of Pilot Parallel fountain pens, which come with a caps that ain’t got pocket clips. Among other flaws. They bloody well have clips on 'em now.
Based on the number of comments on this thread there are way more of us than I thought.