Would this be possible using a field customizer? I haven't used SP extensions yet so if anyone has good resources/documentation that would be appreciated.
Yes that's possible. We will need to hide the column value from a system view. Also stop the same user(user group) from customizing the views, to make sure he isn't able to add the column in other views.
Se in the above image you can change the column value with *** for a specific user group.
More details here: field customizer spfx