Great question — answering as the UphillTech team:
Starting note: Always try to use first available hooks, then if you have no other choice, you can override available templates via your child theme. First in reference below you will find how to override properly woocommerce templates via a theme (avoiding editing the plugin templates) . In your first code snippet, as you can see for woocommerce_single_product_summary hook , you have in order all the different templates that are @hooked in this hook location with do_action() WordPress function: do_action( 'woocommerce_single_product_summary' ); So in your customized code (the 2nd code snippet) you have just replaced the hook , by the hooked template slug (that is NOT a hook) and will NOT...
Full answer by LoicTheAztec: https://stackoverflow.stackexchange.com/a/39064240 (CC BY-SA 4.0).
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