Improving LCP on Hyas Images-processed images

[pensivedog]

It seems hard to get perfect Lighthouse mobile performance scores on a blog or article page with a leading image at the top.

In these contexts, I'm using Hyas Images with loading set to auto, since Lighthouse penalizes lazy loading for images above the fold. My setup in these cases looks like the following, and I'm consistently getting LCP times of 3-4 s, usually around 3.3-3.6 s.

{{ partial "picture" (dict
            "ctx" .
            "src" $image
            "alt" $image_caption
            "class" "img-fluid aspect-video object-cover w-full"
            "loading" "auto"
            "widths" (slice 300 450 600 900)
)}}

Since it's not possible to directly add fetchpriority="high" here, I've added it to the div around this image, which seems to have improved LCP time a little.

Does anyone have any tips, suggestions, or techniques for improving LCP times with images like this?