This question is in my mind for a while.
Now I have 2 RigS of AMD+Nvidia, I use MSIAfterBurner and Radeon Settings for tuning my card.
99% of my cards got very close hashrate as the card that already mod bios (Not sure about power consumption rate).
I know that if you have many many rigs flash gpu bios is very useful, but in my case I only have 2 rigs and I am fine to resetting again when system error or new card installed.
So does flash GPU bios has another benefit that I miss? Should I learn do that?
Like you said it comes down to power consumption rate. If you have no electricity costs and heat etc isnt important than it doesnt make a huge difference.
But if your mining at home and you want the fans to be low speed and GPU temperature low better to mod the bios and undervolt