Empowering the 'User' (hardware owner) should have always been the focus.
From that mindset what makes sense are hardware vendors including a cache of trusted third party root certificates from known other vendors. Today this would include Microsoft, the same said hardware vendor, probably various respected Linux organizations/groups (Offhand, Linux Foundation, ArchLinux, Debian, IBM/RedHat, Oracle, SUSE, etc), similar for BSD...
Crucially the end user should then be ASKED which to enable. None should be enrolled out of the box. They might also be enabled only for specific things. E.G. HW vendor could be enabled only for new system firmware signatures (load using the existing software) rather than generic UEFI boot targets. The user should also be able to enroll their own CA certs as well; multiple of them. Useful for Organization, Division Unit, and system local signatures.
It would also, really, be nice if UEFI mandated a uniform access API (maybe it does) for local blobs stored in non mass-storage space. This would be a great place to stash things like UEFI drivers for accessing additional types of hardware drivers, OS boot bits + small related files, etc. I would have said 1GB of storage would be more than sufficient for this - however Microsoft has proven that assumption incorrect. Still it'd be nice to have a standard place and a feature that says the system ships with this much reliable secondary storage included (or maybe 1-2 micro-SD card slots, etc).
> Crucially the end user should then be ASKED which to enable
except, on the other side of the "strange fellows" are people who rose to executive authority by ruthless focus on control of every aspect of their business, and profit including excluding others who did actual work. There is zero point zero chance of any argument that relies on "should" to work IMHO
this is a political situation by definition -- vastly different yet connected members of society and economics, seeking the rule of law to enable stable markets. hint- some of the same decision makers are the ones that pay to put spy code in your large new TV or appliances.
This is what you get when a programmer designs a system.
The end user wants to be able to just pick up a computer from Best Buy and have it work, out of the box.
Microsoft can't even conceptualize why you would want to run anything but the Windows that came with the machine. If the expected Windows kernel and files aren't there, or have been altered, that is evidence of malicious tampering—malware that must be stopped. (I'm deliberately steelmanning their perspective here.)
Streaming services want a secure content path. Game vendors want protection against cheating. In order to comply with local/regional/national laws, web sites need you to verify your age, and they need to know your computer is not lying (remote attestation). Nobody wants to be hacked.
The incentives for everyone else besides techies align against techies getting to run arbitrary code on their devices. The Secure Boot system is working precisely as designed.
> From that mindset what makes sense are hardware vendors including a cache of trusted third party root certificates from known other vendors. Today this would include Microslop, the same said hardware vendor, probably various respected Linux organizations/groups (Offhand, Linux Foundation, ArchLinux, Debian, IBM/RedHat, Oracle, SUSE, etc), similar for BSD...
IMO systems should be shipped in "Setup Mode" by default with no keys preinstalled. On first boot which ever OS you decide to install should be able to enroll its keys.
This way it is entirely agnostic of any cherrypicked list of "trust me" vendors. You'd still have most of the benefits of easy secure boot enrolling for those that don't know what it even is/how to do it while also allowing easy choosing of other OSes (at least on initial first boot).
The main problem currently is option-ROM which has a tendency to cause the system to not even POST if secure boot is enabled without MS keys. Recently bricked a MoBo this way and even though it has 2 BIOS I can't actively choose which one to boot, it just has some "trust me, I know when" logic that chooses... well guess how well that is working for me...). The Asrock board I replaced it with though has an option for what it should do with such option-ROM when secure boot is active (don't run, always run, run if signed, ...)
> The user should also be able to enroll their own CA certs as well; multiple of them. Useful for Organization, Division Unit, and system local signatures.
Isn't this already the status quo??
> It would also, really, be nice if UEFI mandated a uniform access API (maybe it does) for local blobs stored in non mass-storage space. [...]
I think UEFI is already complex enough and most of this can in a way already somewhat be handled by the EFI System Partition, e.g. systemd-boot can tell the UEFI to load (file system) drivers off of it (https://wiki.archlinux.org/title/Systemd-boot#Supported_file...), I don't know if UEFI technically supports other types of drivers to be loaded.