To what extent is this possible for actual metal hardware? I'm sure lots of us are running PXE/TFTP systems and HTTP would be a heck of a lot simpler.

Having http as an alternative to tftp is a nice win. The range of things that can run an http server is much bigger than tftp

>Additionally, adding the TLS layer brings back the missing integrity and confidentiality guarantees and thus paves the way to move critical boot components out of the trusted network, possibly even to a remote location/Cloud.

Doesn't secure boot already provide this or am I misunderstanding something? I suppose secure boot only provides integrity but not confidentiality although I'm not sure how much confidentiality matters given we're just talking about the kernel here