It would appear that without a GPU or APU the card will not boot, except p-e by pressing F1 on power-up.
More info here: https://www.reddit.com/r...

I own the board, but I can't answer your actual question. However, the MSI B550i Gaming Edge Wifi can do what you are looking for.

From my own experience: leave it without an APU, take a 5700g. ECC only works unregistered anyway. Your NAS won't start with cheap server RAM from Ricardo. Once you have a problem with the NAS, you take the box apart to remove the 10gbit card and install a graphics card just to boot into the bios...

I've done it all and believe me, it's annoying :)