Proper end plate orientation really does matter.
The base plates for the Pine 125X, G1 and G2 Superpave gyratory compactor molds have lips that rest on a ledge at the bottom of the mold. An upside down plate will lead to density differences if you are compacting to height.
Top plates for the Pine 125X and the top and bottom plates for the GB1 have a beveled edge designed to face away from the asphalt material to prevent binding of the plate with the mold wall during gyration. Installing the plate upside incorrectly may cause binding between the end plate and the mold wall that could affect compaction.