https://opengarage.io/faqs/ is where it talks a bit about it. It also has a link for downloading tools to flash 1.0.1, which I eventually managed to do.
Unfortunately I can’t succeed in any OTA updates or flash any new bin files.
The OTA gets as far as “rebooting”, but nothing happens. When I try flashing other versions the device usually enters a bootloop (continuous startup sound) or doesn’t turn on at all.