I want to share with you guys my mod, it works in all my cards, i used the one with the lowest ASIC (76,8 %) to show how this bios behave, i'm sharing the most stable bios because; i have a custom one for each card, some with lower mem volt and/or core volt.
I was aiming for the highest Mh/s with stock volts, then undervolted as much as possible, those settings allow the card to run at lower power consumption with ZERO GPU Memory errors.
Ignore the Polaris BIOS Editor because those are test settings are not stable (MEM volt is too low), here is a screenshot for solo mining ETH:
Dual mining is good too:
Tested for 48 hours and so far no reboots, driver crashes, etc, 100% stable in all my cards, you may need to lower volts settings or increase them a bit.