[the_why_of_y]

That simply disables Secure Boot, which is not what sanlyx wants because you don't get the security benefit of replacing the manufacturer provided PK and/or KEK with your own so that only images you signed will boot.

[floatboth]

Sure, you don't get your own secure boot, but the point is, it's not "omg apple lockdown no third party OS possible at all"