Do you refer to the entity-id name convention or are you talking about the UI name? I’m not sure if I fully understand this, because the attributes.friendly_name is only frontend relevant, it wouldn’t change any existing behaviour regarding entity_id or configurations, except if there is a name and a attributes.frienldy_name defined and the name is different to the attributes.friendly_name:
Before: Now the friendly_name is silently overwritten, and name is used.
After: The friendly_name is used for the initial setup of the sensor.
Still only talking about the initial config.
But I don’t know all things of HA regarding names, the customize.yaml is quite new to me. As this affects the friendly_name, I’m pretty sure this cannot overwrite name at this stage…otherwise it would also impact the entity_id…which it doesn’t :). How well is the test suite? We could find it out with implementing it and looking into the test results? 