To exclude Wishlist button on specific products belonging to certain collection, please use the below construct at appropriate location in your theme
Individual Product page
{% unless product.collections contains 'collection-handle' %}
//code snippet of smart wishlist
<div id="smartwishlist" data-product="{{ product.id }}" data-variant="{{ product.variants.first.id }}"></div>
{% endunless %}
Collection/Category Page
{% unless collection.handle contains 'collection-handle' %}
//code snippet of smart wishlist
<span class="smartwishlist" data-product="{{ product.id }}" data-variant="{{ product.variants.first.id }}"></span>
{% endunless %}If you want to exclude the button from products belonging to multiple collections, you can use and operator
{% unless product.collections contains 'collection-handle' and product.collections contains 'collection-handle2' %}
//Smart Wishlist Snippet for single product page
{% endunless %}
{% unless collection.handle contains 'collection-handle' and collection.handle contains 'collection-handle2' %}
//Smart Wishlist Snippet for Collection pages
{% endunless %}