I also have a coreboot KGPE-D16 but am using different accessory cards.  I took a look at the specs on your Hyper card and compared it to KGPE specs and I think one or more of the following might be the issue:
* It looks like the Hyper card is a PCIE 3.0 device and the KGPE-D16 has PCIE 2.0 slots.