Revisions C and later of the PXIe-4136/7, and revisions H and later of the PXIe-4138/9 now include an additional 4 connection points for chassis ground on the main front panel connector, revealed by 4 extra holes in the front panel sticker overlay. Likewise, the connector kit that ships with these new SMU's now includes 4 additional POGO pins (spring loaded) which press onto those new connection points. See image below. These new connector kits have an additional internal screw for connecting to chassis ground.
Both the new and old connector kits are compatible with both the new and old modules. However, only the new connector kit combined with the new module provides the user with a valid chassis ground connection in the connector kit. For any other combination, the user will have to use the lug towards the bottom of the SMU front panel for a chassis ground connection.