How do I pick an object that is a member of two families, and evalute variables from both families?

I'm trying to get around the fact that Construct isn't able to detect whether the player collides with any solid, so now I need to be able to determine if objects belonging to a specific family is also in the family "Blocking".

How do I evaluate whether a family object's instance is also member of the "Blocking" family, and how do I pick that object if "Blocking" has a variable that is set?

You can pick Blocking instance by UID. This will be the same instance, but you will be able to access its variables.

Player on collision with SolidFamily
BlockingFamily pick by unique ID = SolidFamily.UID