Needed to create a baffle for the widely available and inexpensive Dell branded Mellanox ConnectX-4 LX cards that are slightly different in layout than other half height versions I've seen.
The card is very secure once the baffle is screwed in and have had zero wiggle when inserting and removing optics.
Use the original screws from the metal bracket that came with your card (screws go from the top of the card into the baffle feet.
Also use the screws from the Lenovo baffle that ships with your device for securing to the chassis.