Device makers doesn’t sound like operating system to me. Just need to make sure there is a distro that the device comes with which does this. So if you make ToBeReinstalledOS which only comes with an age checkbox and USB media creation tool to the bare minimum compliance required and no network drivers to prevent accidental age verification. Your device is compliant and can be sold in authoritarian countries.
Device makers doesn’t sound like operating system to me. Just need to make sure there is a distro that the device comes with which does this. So if you make ToBeReinstalledOS which only comes with an age checkbox and USB media creation tool to the bare minimum compliance required and no network drivers to prevent accidental age verification. Your device is compliant and can be sold in authoritarian countries.