So ...

This time I am going to use another well-coded, tiny (26 KB) plugin called Broken Link Checker.

Here it is:

https://wordpress.org/plugins/broken-link-checker/

So let's see the usual speed tests ...

Here are my results before installing the plugin ...

... and the result after installing and activating the plugin:

No more comments needed I guess ... The plugin is almost invisible ...

So, let's see how it works ...