>I don't see any advantage to involving Microsoft in the boot process.

Good point. Me neither, never have,

But if they're already there within the PC in some way or another, ideally they should gracefully be able to accomodate Linux under UEFI as easily as it still works when using BIOS.

>in effect you're proposing different boot paths, and different UI/UX depending on whether the system is Linux-only or dual boot Windows Linux.

Not proposing. Been living it for decades. It's only broken under UEFI.

Even on my average pure Windows machine, I normally have about 4 distinct boot paths for each OS using various instances of the NT6 bootloader. Not counting the option of whipping up an emergency boot floppy which can still be made for modern Windows use if all else failed.

Experience has shown, the more viable boot paths, and the fewer obstacles, the greater reliability.

>You seem to think Microsoft wants to be in the business of executing arbitrary and unsigned code

Nope, that's just how they started out and ended up outgrowing IBM. I remember it well, those days are long over.

Likewise, there should never have been any need for Linux to involve any Microsoft code or signing, like SecureBoot, in order to perform on the most secure new PC's without requiring any different default UEFI settings than Windows.