You’re 100% right. I also screwed up that media query syntax. It should just be width or inline-size. So fixed is like:

if(
  media(width > 900px): repeat(auto-fit, minmax(200px, 1fr));
  media(width > 600px): repeat(3, 1fr);
  media(width > 300px): repeat(2, 1fr);
  else: 1fr;
); 

if(
media(max-width > 300px): repeat(2, 1fr);
media(max-width > 600px): repeat(3, 1fr);
media(max-width > 900px): repeat(auto-fit, minmax(250px, 1fr));
else: 1fr;
);

You may want to reverse the matches. You say “first match wins.” If so, the 600px and 900px matches will never execute since they are both greater than 300 and that will always win.

Interesting. Good observation.

Now if your traffic is more evenly mixed then maybe it makes sense to use them but have fallbacks or polyfills, or use as a progressive enhancement. But I think it still doesn’t makes sense to feature them from a broader ecosystem perspective. Chrome is the new IE. It can do what it wants because it has so much market share. A lot of Chrome only features will never become a standard and standards are what we should be building for. Chrome only features belong in the “stuff to keep an eye on section”.

That said. There’s some cool stuff in here. Thank you for writing them up.