alt Hacker News> Maybe conceptually you will be able to run some kind of open operating system with your own code
Why do you think they would even allow this? If you think that governments don't have the incentives or the means to criminalize running non-approved OSes, or the unauthorized use of non-approved hardware, you're insufficiently cynical.
It's hard to enforce, and not dangerous enough. Accessing something serious from this unapproved code is the opposite, and is being locked down. Try running your own code on your phone's baseband processor, or boot your own OS with Secure Boot on.