Lately I’ve been leaning on Utopia for fluid type/space and Responsively App to preview across breakpoints, especially between 360 and 1440 px. If you’ve got a lighter alternative or a smarter way to handle responsive images for 2x/3x displays, I’m all ears.
I just run two Chrome windows with Device Toolbar instead of Responsively — lighter and fine for 360–1440. For the ‘2x/3x’ issue, ditch x-descriptors and use width-based srcset with a truthful sizes (e.g., sizes=‘(min-width: 60rem) 50vw, 100vw’); it picks the right file across DPR/zoom like a barista choosing cup sizes — MDN’s guide is solid: Using responsive images in HTML - HTML | MDN.