I found a 2-year-old thread stating that the MSPC doesn't work if you use shortcodes. To my dismay, it still apparently does not work, i.e., the feature has not been added.
This should be implemented because many sites are single page/product sites where the landing page is a product page. Establishing a product page to be a landing page requires that you create a new page and use a product page ID shortcode to embed the product page. If I want to use the MSPC on the landing page, then I am simply out of luck.