> b) Linux becomes non-bootable on common hardware.
I don't consider any of this UEFI-locking to be a technical problem. It's an antitrust-problem.
Because the reason Microsoft does it is obviously because it tries to lock out competition.
So the first thing needed to combat this, is to abolish any law that protects this kind of shenanigans, namely the DRM anti-circumvention provisions of the DMCA and similar laws. And the second step is to go in with anitrust law. hard.