Woocommerce Product Waiting Room Plugin

This plugin can be activated on any page using a shortcode. If too many users are accessing a page, then this will engage the waiting room. The waiting room will let users in as users leave the page. A common use will be for a Woocommerce product page where logged in customers attempt to add a product to their cart and checkout. When a popular product is released, the server can be overloaded when 1000+ customers attempt to add the product to their cart. By blocking access to that product page and placing the customer in a waiting room, the server load is reduced.

The waiting room should be a simple Wordpress page (e.g. https://ultracornhole.com/waiting-room) that has information for the customer to let them know what is happening and approximately how long they have to wait. The plugin is to have an admin interface to all for adjustments such as the threshold number of customers accessing a page with the waiting room shortcode. Also, settings such as what to display to customers waiting in the waiting room.
Attached is a boilerplate plugin for this project.