[Avamander]

Well no, you can keep Secure Boot enabled (which you should) and disable SG/DG and be able to boot or install Linux.

[bilegeek]

That's a relief. Without UEFI, the boot drive is limited to 2.2TB, hampering upgrades.

[2000UltraDeluxe]

The PDF linked to further up this thread describes the process of trusting the 3rd party Microsoft CA that the original article mentions has been distrusted.