Dawn Theme - custom tag for certain products on Collection all pages - metaobjects?

Hi and sorry for the delayed response you can do that by including more cases inside the if statement like this

{% if card_product.handle == 'A' or card_product.handle == 'B' or card_product.handle == 'C' %}
Customize

{% endif %}

or this way

{% assign custom_handles = "A,B,C" | split: "," %}
{% if custom_handles contains card_product.handle %}
  Customize

{% endif %}