All the details are right in the article as well as a link to a git repo so I'm not sure what there is to speculate about. If you have an issue with the actual benchmark you can certainly point it out, but otherwise you're basically asking us to restate the contents of the article when the article does a much better job of explaining these details.
Hmm I’m not sure you’re responding to what I’m saying. The C code is not an apples to apples comparison with the custom assembly when comparing the speed of an indirect call to a direct call. Do you deny that?
Yes I do deny that, especially since the article literally addresses this issue explicitly and takes care to avoid that, along with a git repo that you can use to verify this for yourself. If you have a specific criticism to make then you should go ahead and point it out in a non-vague manner instead of speculating.