Filters:after appears to be ignored

After reading the CI User Guide (https://codeigniter.com/user_guide/incom...er-filters),  from my- evidently limited- understanding, AFTER filters are applied to any response from a controller, once it has completed.

As such, I can’t see why they shouldn’t work on a response that is destined for a client-side JavaScript routine (that doesn’t update the client’s page)… after-all, these are also HTTP responses and should be processed in a similar manner to any other response by CodeIgniter\HTTP\ResponseInterface, which all the filters rely on?

What am I missing?