You know that this feature only works because Microsoft added it to the requirements of the Windows Logo program for x86 based computers almost at the last minu

You know that this feature only works because Microsoft added it to the requirements of the Windows Logo program for x86 based computers almost at the last minute. Mainboard manufacturers would otherwise cut corners and add the MS signing key as the only unchangeable key to the system. At the same time, MS specified for ARM computers that want to run Windows that the key must be fixed and irreplaceable.