The Xpert DIMM with the display installed requires more space than a standard module. To avoid mechanical interference when two Xpert DIMMs are installed, the display modules come with two equally-functional interface ports, allowing different orientations. While the display of DIMM A will stick out on one side, the display of DIMM B should stick out to the other side. (Note that while mechanically attaching two Xpert DIMMs to one display is possible, this won’t function properly.)
The LED module for displaying technical data or a marquee needs to be attached to the top of the Xpert DIMMs.
Just use the second connector if the display would collide with any other components using the standard connector.
Corsair has always labeled their DIMMs, leaving no question as to their capabilities. In this case, CL 2.0-2-2-5 timings are ideal.