Benny Windolph

This plugin allows you to add products to specific variations in WooCommerce. It synchronizes the quantities of these products with the main variation and removes the quantity change and remove buttons for the added products.

Force Sells for Variations

Adds products to specific variations and synchronizes quantities. Removes quantity change and remove buttons for these added products.

MattGeri

WP Geeks

Force Add To Cart for WooCommerce allows you to select a product which will automatically be added to the shopping cart when another product is added to the cart. Simply visit the “Linked Products” section on the edit product page and choose the product to be force added to the cart when that product is added.
Additionally, you have the ability to select whether a visitor is able to remove the product that was forcefully added or to restrict removing the product from the cart.
The plugin works with both the classic cart experience and the new React based cart block.
Built by <a href="https://wpgeeks.com" rel="nofollow ugc">WP Geeks</a>.
<h3>Usage</h3>
Once you have installed the plugin, you will find the settings on the Edit Product page in WooCommerce, under the section Linked Products in the Product Data metabox.

Force Add To Cart for WooCommerce

A WooCommerce plugin that allows you to force add a product to the shopping cart.

Force Sells for Variations vs Force Add To Cart for WooCommerce