I like this. I like having the same boot process everywhere, by which I mean how to set it up and control it, so, unified kernel images on ESP partitions 
This does already kind of work with U-Boot, but its EFI runtime doens’t support storing EFI variables, so things like setting NextBoot don’t work on U-Boot to just temporarily boot a different kernel once. (And sure, could do that with kexec, but that’s not the point :-P). But U-boot does already support systemd-boot & UKIs, and it does pass the updated memory map through correctly, so no need for an 8G memory DTBO
I’m definitely going to give EDK2 a shot as soon as I have the time. This should allow me to have the exact same setup as on my workstation. 