I understand the need for certain functions that are only in admin area, it's probably better to just require the files if necessary rather than forking a remote call.

Even if you do the remote call, at least make it non-blocking, and make sure the child process doesn't terminate when the parent process is terminated (due to the non-blocking call). Emulate what wp-cron.php does. But then again why would we need to do that when we already use cron.