Unfortunately, it looks like there's something in the way the PCIe card reboots that upsets HP servers.
When I reboot the CCR, the server INSTANTLY hangs, with errors like "Uncorrectable Machine Check Exception (Board 0, Processor 1, APIC ID 0x00000000, Bank 0x00000013, Status 0xFE200000'000C110A, Address 0x00000000'80500000, Misc 0x44FC3816'00402086)" and "PCI Bus Error (Slot 2, Bus 0, Device 2, Function 0)"
Has anyone managed to get these cards working with enterprise-ish servers at all? I can understand that a normal PC without all the failsafe/monitoring would probably not notice, or even mind, that a PCI card vanishes, but these bigger servers obviously do!
This SPECIFIC host is a HP DL360 G9, with 2 x E5-2687W v3's, but I suspect that almost all servers are going to have a similar problem.