Flash RX 480 to RX580 for Mojave?

My friends selling me his brand new RX480 for $50, I'm currently using the 1050 non-ti with High Sierra.

I read online that I could trick the system into thinking this is a natively supported GPU by flashing the firmware on it?

If so, since they gave the same chip anyways, would Mohave be natively supported like a regular 580?

Thanks.