Subdomain Pro plugin can convert  Post  ,  Pages  ,  Categories  and  Custom Posts  into subdomains. Just create Posts, Pages, Categories or any custom post type. It will automatically be converted into Subdomains. So create as many subdomains as you want and it may require a wildcard subdomain addition setup but most of the Host already do it. This will increase the performance of the website. It will also help in SEO.

Resources :-

• Convert your posts and pages into subdomains.
• Convert your categories and taxonomies into subdomains.
• Supporting all custom post types and taxonomies.
• Woocommerce compatible.
• SEO friendly URLs.
• Null conflict.
• Delete option for post types and taxonomies in admin settings page.

Here is the configuration for the wildcard subdomain.