Use core's AVIF with webp format image effect (instead of webp)

Used this to convert all image styles in recipes dir:

find recipes/ -name "image.style.*.yml" -exec sed -i 's/^ *id: image_convert$/ id: image_convert_avif/' {} +

Postponed until 11.2.x is required

Probably safer to commit this to the next minor version of Drupal CMS, rather than 1.1.x. It will need a change record to explain how to make this adjustment to existing sites manually.

📌 Update to Drupal core 11.2 beta Active is committed, so this is unblocked.