I believe points 1 and 2 could be addressed by implementing a trust-on-first-use model whereby the customer can set an initial signing public key for the PSP, w

I believe points 1 and 2 could be addressed by implementing a trust-on-first-use model whereby the customer can set an initial signing public key for the PSP, which is then used to sign specific boot parameters. That way, as the customer, I can tell the PSP that I'd like to either require PSP-mediated secure boot, or permit boot if the PSP is disabled. OEMs and vendors selling to enterprise customers can pre-sign it for convenience, and tinfoil hats like me can disable it. Everybody wins. But we don't even have the choice.