Flashing is easy with SPI programmer and appropriate voltage adapter / clip. Will good things now follow
I've only heard that modded BIOS can work on mobiles 1000/2000. Desktop is code 43 which seems to cover a lot of things, not just modded BIOS. For those fortunate enough to run a mobile modified VBIOS nobody seems able or have tried to find out what's different to allow this.
Easy enough with checksum fixes, at least with Pascal but hashes are another matter.
HULK cert is supposed to allow mods too but haven't heard of anyone using this method.