There are currently two product tags that can be added to products in your store that relate to the Smart Cart.
To add or remove any of these tags on a product follow the documentation by Shopify, Follow step #1
Items with this product tag are NOT displayed as line items in the Smart Cart and their quantiles are not included in the item count. Although, their line totals ARE included in the cart subtotal.
This will hide the quantity selector for any items containing this tag.
Items with this product tag are visually displayed as line items in the cart and the item count is included. But, the subtotal is NOT included when calculating the free shipping threshold.
Finishing This Up
Once you have gone through your products in the Shopify Admin, follow step 2 of this guide to finish up by clearing the product caches.