Let me add that the typical GrapheneOS user will probably prefer to install the OS themselves rather than trust what comes preinstalled.

This is emblematic of a misunderstanding technologists often have about the law. We try to treat it like code we can exploit and hack around. But there is no compiler deterministically producing outcomes. Of course, this misunderstanding is often bolstered by the accurate observation that lawyers and businesses find loopholes and favorable interpretations that to us appear much like the exploits we propose. The critical element that's often missed, though, is the human one. To get away with an exploit, to have the case law updated to reflect your favorable interpretation, you need power, influence, and alignment on your interests. There are tax "loopholes" now that are commonly used but in a prior era, under the same laws, would have seen you dragged into court and eviscerated. If you tried your cute SD card trick a judge would tear you a new one. If Microsoft tried it, they could maybe talk to the right people before the case and come to an understanding that this little loophole was convenient for dev devices or something, and convince a judge to rule that they could do it, but only if accompanied by some external age confirmation they could self-attest to, with some wording that makes it clear that the trick is only usable by large and well-respected institutions. The law is not an impartial arbiter that you can outsmart. It's the enforcement mechanism for multiple tiers or rules that bind different classes. This age gathering law is a classic moat law. It exists to prevent outgroups from shipping software that's incompatible with this age communication system, and in a business-to-business context serves to establish obligations between ingroup members. Any other clever interpretation of the law will be discarded regardless of specific wording.

Sounds like it exposes a ton of attack surface. Better to just have a card with a link to the webinstaller, probably.

I'm sure noone in the legal system of California would notice that trick!