CSS in build/css/templates/ is enqueued only when the request matches: reserved (404, search, archive), CPT by name, or page template slug. Add SCSS under assets/scss/templates/, run npm run build; no PHP config needed.
Core overrides in assets/scss/blocks/core/ are per-block via wp_enqueue_block_style(). Third-party overrides in assets/scss/blocks/third-party/ load only on singular content that uses those blocks. Core block assets stay separate (should_load_separate_core_block_assets).
All theme-built CSS/JS use the built file’s modification time as the ver query string. Each npm run build updates cache; no manual version bump.
Dominant color is calculated on upload (Imagick or GD), stored in post meta _dominant_color, and used as a background placeholder until the image loads. File: inc/performance/dominant-color-images.php. Supports standard image types and core image/cover blocks.
Adds fetchpriority="high" to above-the-fold images (featured + up to a few from content) on singular pages; removes loading="lazy" for those. File: inc/performance/image-prioritizer.php. Complements LCP optimization.
Generates WebP for JPEG/PNG uploads (all sizes). Imagick or GD. Helpers: \WebDevStudios\wdsbt\get_webp_url(), get_webp_file(), browser_supports_webp(). Regenerate via Tools > WDSBT Settings, WP-CLI wp webp regenerate, or regenerate_webp_for_attachment(). File: inc/performance/webp-uploads.php.