RX 5700 XT bios downgrade to Non XT for better power consumption and more hashrate

I feel like the XT bios is just a way to scam more money out of existing hardware. There is no difference in the hardware. The XT bios allows for more overclocking and higher power consumption. I've been wanting to do this experiment for awhile. I wanted to know what would happen if I put a non XT bios on a XT GPU. I seemed to pickup a few megahash and save about 15-20 watts of power. The non XT bios allowed me bring down the core voltage with crashing the cards.
Android Power Meter I'm using
https://www.amazon.com/gp/product/B071KXNDW7/ref=as_li_tl?ie=UTF8&tag=fintechcomm0f-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B071KXNDW7&linkId=349cd511b5974c248c1e5513fa03e348