Most of the RX series DID NOT have a dual bios. Dual bios was more popular with the older cards from the Radeon era. They also might be more common now but most RX series cards DO NOT have a dual bios. I think the only one that had one was some special Sapphire brand.

So he needs to becareful when modding to make sure he doesn't mess up. If he messes up there is a way to recover a crashed bios by having to short 2 pins on a chip location on the PCB and using DOS he can reflash with the stock bios. Hence if you do this, ALWAYS make sure to make a backup of the bios.