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