And I fixed it! Didn’t realize that Site Ground had site cache turned on by default so replication was taking longer than normal. Flushed cache and turned off. Changes now appear promptly.
Site Ground Doc: https://www.siteground.com/tutorials/supercacher/static_cache.htm
Other forum post that lead me to this: https://ww.wp.xz.cn/support/topic/child-theme-css-not-updating-not-a-chache-issue?replies=3
Interesting. I was using firefox and brave dev tools and wasn’t seeing the change from 80% to 132 as i was just testing. Seems like it was taking quite some time for those updates to apply. Any reason for this? If applied within the customizer, changes are made almost instantly.
Appears nothing is wrong with using the Child CSS as i thought, just replication is taking quite long.