Look at your first and last links, Seed, they call them Hemerocallis 'Kwanso' flore pleno-- all in one. You're right. They don't know the difference.
I've never looked beyond the difference in color and that Kwanso is sometimes only double and sometimes triple. Here's Flore Pleno from years ago. I'll continue to look for an image of my Kwanso. They are usually the last of my daylilies to bloom.
I'm also beginning to wonder what the difference truly is.