AFAIU at this point it's quite early, and the way they're working on it at the moment is to remove the ROM flash chip (which, depending on the motherboard, may

AFAIU at this point it's quite early, and the way they're working on it at the moment is to remove the ROM flash chip (which, depending on the motherboard, may require desoldering the chip) and flash it with a SPI programmer. If you're up to that stuff, I think they'd be happy to have your help. Otherwise maybe you should wait and hope they'll figure out how to flash it from Linux, and make it robust enough that there's a relatively low risk of bricking your system.