for someone not trying to not to lose warranty, but 1900 on memory is excessive overlocking. if you cant restore stock bios when the card dies. then it will be difficult for manufacture to read the bios chip without totally disassembling card to read the bios chip.
the way things are, is better not to mess with the bios at all. I do hope in future, not distant, you can buy gpu boards, gpu memories and gpu dies, that will make things much easier and manufactures then won't come with the bs and say "you did something to it and we are not honouring the rma." They put third class capacitors, memory chips and blame users, whathehell.