Hi,
I've activated it on a per product basis in the HikaShop configuration. So in each product on our demo website, you can activate the waitlist button and it will appear on the product page when the stock is 0 for that product.
Regarding the compare feature, it's either activated for everything or for nothing. And the design of the template isn't made to accomodate that feature so we decided against activating it on the demo website, unfortunately.
Note that it will take a few hours for you to see the change.