Creating not inherited page property field




we are using AEM 6.1, SP2 in a blueprint/livecopy environment. I would like to add a field in the page properties which should not be inherited to livecopy page - so there should be no lock symbol in front of the field. Is this somehow achievable - meaning that fields are not connected/synced to blueprint page?

I'm aware that I can exclude the page property field from being updated via "CQ MSM Content Update Action" Config but then the field is filled in when I create the livecopy initially although it's not updated via rollout.