We use the fetchpriority attribute to tell the browser that some CSS files need to be loaded first (because we use the "defer CSS" option so CSS loading is not render blocking).
We also use advagg_bundler to have better control over how many CSS bundles we want. But it discards the fetchpriority attribute and groups assets with different priorities.
foo:
css:
theme:
source/foo.css: { attributes: { fetchpriority: high } }
fetchpriority attribute disappears from the aggregated CSS link tagsAdvaggCssCollectionGrouper::group() should use the fetchpriority as a criteria to create groups.
💬 Aggregate and bundle only JavaScript with defer without forcing all to defer? Needs work could also be a solution to this.