it highly unlikely it will do any harm to your motherboard even without the software fix. you have to understand how chip work which i will not go into detail but i'll give you a idea. most of the chip can take 15 to 20% more power to it as long as you are not doing it like non stop stable power to it. some can even go up more and that is how they are design to it. the "KEY WORD" is voltage spike and not constant high voltage. so if it only like a few millisecond or nanosecond of high voltage. it should be ok.
it says the RX480 can spike as high as 6.74 amps (6.74 x 12 =80.88) which is 5.88w over 75w limit "spike voltage" 7.84% ish? depending how long that "spike is" it should be ok. you still haven't hear story that say "My...