Your use of non-UGW permission features in production

Hi All,

I'm prepping for my RHCSA, and was reading up on ACL's and setting alternate umask values. I understand how the commands work, but it seems like I would rarely use these. Can you think of any situation from a production environment where you have needed to set / use ACL's or alternate umask values for a user / group? I'm mostly wondering how these are practical / relevant for a sysadmin in day-to-day work.