WTR Pro CPU throttling

mine definitely requires both PCI devices to be passed through, is yours the 4 bay or 2 bay?
2 bays but the motherboard and BIOS are common so it should work too (AR5000-MI2). You can take a backup of the BIOS chip with a CH341 programmer to be safe, but the chip is located behind the cooler - so you have to basically remove all the screws (and repaste the CPU).
 
maybe someone on the manufacturer's discord channel could reach out to them and ask whether they can make an official bios for all hardware versions? This seems promising.