EMMC booting issues

EndtheFED

You could try this https://github.com/armbian/config. You can add it to your OS but, you will need the dependencies (you will need to find working ones or add ppas) If  that's too complicated. It's built into Armbian. You boot OS on SD. Then Run Armbianconfig. You can install to USB3 or EMMC. I'm using a HD dock/hub. It's fast but, the OS is still in development, as are all the OS's. Itried USB3 memory stick too (get one with heat synks and no case it gets hot!!!). Way faster than EMMC It uses the SD for the boot record then boots the OS.from where you moved it too.
It will be a while until you can get a supported OS. Donations to Firefly or your preferred OS could help speed things along. I'm just waiting patently like you. I have no connection to anyone. I just own the board lol