No need for a child theme. Just rename your layout file like this: catalog_product_view_id_{id}.xml

Source: https://devdocs.magento.com/guides/v2.4/frontend-dev-guide/layouts/product-layouts.html

No need for a child theme. Just rename your layout file like this: catalog_product_view_id_{id}.xml

Source: https://devdocs.magento.com/guides/v2.4/frontend-dev-guide/layouts/product-layouts.html

Or create a layout handle catalog_product_view_special.xml with your special layout and apply it on your products using <update handle="catalog_product_view_special"/>

HTH, Tom