To update server-wide php configuration, we need to edit php.ini file at

/usr/local/lib/php.ini

After making change, run command to update cagefs setting

cagefsctl --force-update

You should see the change reflected when checking php info on a specific hosting account.

Php.ini location on php info page shows usr/selector/php.ini which is a virtual link inside cagefs for each cpanel user.