015.042.000.000.000000 supports:
4096 MB, GDDR5, Hynix H5GQ2H24AFR
4096 MB, GDDR5, Elpida EDW2032BBBG_DEBUG2
015.043.000.001.000000 supports:
4096 MB, GDDR5, Hynix H5GQ2H24AFR
4096 MB, GDDR5, Hynix H5GC2H24BFR
The rest of the BIOS appears to be majority the same thing.
So, Maybe we can test BIOS from another brand (ASUS, XFX and so on) with same vRAM??