Is there a Dynamo solution that bulk inserts all the available types in a family, inside the project. Perhaps inserting them at a certain distance apart–so they are not overlapping in the scene.
You could collect all family types by category, generate a 2D point grid and place them as family instances. Detecting their size would be difficult however as elements size are all dictated differently - maybe collect the first placed instance and use its bounding box, or use Python to search for a possible width/depth parameter to retrieve. If your families use different hosting methods (loose/wall etc.) then that would be very complex to handle, I’d focus on just point/level based first.
You’ll get better engagement from the forums if you show you have begun developing a solution, but hopefully these pointers help you begin with something at least.