Reran install as you asked and saw the following, not sure these warnings will be a problem, while I had time I also ran the install on another machine with the same specs and it worked normally after initial install and before a yum update, after yum update it also has the same problem.
Device (42:00.0):
42:00.0 Network controller: Mellanox Technologies MT27500 Family
Link Width: 8x
PCI Link Speed: Unknown
Device (42:00.0):
42:00.0 Network controller: Mellanox Technologies MT27500 Family
WARNING - device 42:00.0 The MaxReadRequest size is set too low (512 bytes) and will affect performance.
Please consult your server's vendor and if possible change BIOS settings or use setpci to configure MaxReadReq to 4096 bytes.
/sbin/setpci -s 42:00.0 68.W
2xxx
Change to 4096 bytes:
/sbin/setpci -s 42:00.0 68.W=5xxx
Installation finished successfully.
Attempting to perform Firmware update...
Querying Mellanox devices firmware ...
Device #1: