@NightlyH It is indeed. If your machine of choice meets the minimum specs, I can add you to the development coordination thread where several others have been testing pre-releases and offering feedback. Be aware that updates may be infrequent, though.
@MoerBoer As you know, Linux Live USBs work much the same way, as do builds of Fienix and Raspberry Pi OS. That's the advantage of going with a bootable image rather than a stripped down installer, the system can use it the moment it's downloaded and restored to disk. In order to ensure reliability with Open Firmware however, please be advised that this feature will require a specific model of pre-approved USB drive that the user will need to purchase ahead of time. You may attempt to use various other forms of USB media, but due to Open Firmware's fickleness with USB devices, your mileage may vary if so chosen.
@amishallin It should fly.