Hi
wishlists uses ajax call to load Add to Wishlist buttons during page loading, in order to solve any possible cache issue
The loading time that you see is just due to the fact that admin-ajax won’t benefit from any cache, and it isn’t realted to heavy plugin execution
This can be easly tested by loading plain wp-admin/admin-ajax.php: it will fail to a 400 error by default, without executing any specific code, but it will take some time (1.19 sec during my test) because it won’t be provided by cache
If you don’t want to load Add to Wishlist buttons via ajax, you can disable this feature from WP Dashboard -> YITH -> Wishlist -> General
One final note: testing your website, I see that load ajax call is performed even when there is no Add to Wishlist button to load
This is definitely an error, that we will solve in next plugin version
