Empty custom Prop in driver

[tichy]

Holy Hell, I just found the solution here:

Problem with "Use Self" and drivers

a little late to the party, but i was just in the same situation for a rigging issue, and found the “proper” solution with self expression, to access the parent of a driver (a driver in modifier, for example, would have its parent an object parent) you can use self.id_data to access the parent datas. In my case it allows me to access the object custom props. I bet it would work in your use case also Cheers

Just use self.id_data[“propname”] to acces self properties.

GORGEOUS!