prevent responsive images from upscaling

I had started searching for ‘prevent background images from upscaling’…. ok never mind not the problem i actually currently have. My problem is responsive images–srcset and all that

In particular, somehow Drupal is add

See also

Same person also posted about it here

See also

Not particularly useful:

WordPress support in dealing with srcset in general, but not the upscaling issue i’m dealing with,

I filed this issue:

A site builder can configure a responsive image style to prevent upscaling

And updated with this great issue: